Annual Review
2020

Molecular Photoscience
Research Center

Kobe University

PrefaceThis annual review provides a summary of the research activity of Molecular Photoscience ResearchCenter for the 2020 academic year. We are further promoting advanced research and international
collaboration on molecular photoscience and related topics. Any constructive comments and questions,and any suggestion for collaboration research are welcome.
Since 2017 we have been running joint usage/research project on molecular science in the terahertz
frequency region, which is open to domestic universities and research institutes. In this year 36 joint
research projects were accepted, and the research area spans from solid state physics, biophysics, solution
chemistry, polymer science, photochemistry, theoretical physics and chemistry, so on. In this year we also
started a series of seminars for the four research areas (solar energy conversion, high-resolution
spectroscopy in gas phase, spin material physics, and hydration of soft matter) in the terahertz molecularscience. The research center will continue to make efforts to push forward international and domestic
collaborative research.
April, 2021
Keisuke Tominaga
Director of Molecular Photoscience Research Center,
Kobe University

Contents
Members

5

Research Activities
Laser Molecular Photoscience Laboratory

6

Terahertz Molecular Chemistry Laboratory

16

Terahertz Material Physics Laboratory

24

Original Papers

37

Invited Talks

40

Presentation at Conferences (International and domestic)

41

Presentation by Graduate Students and Postdocs

43

Books

46

Other Publications

47

Lectures to Public

48

Awards49

Conference Organization

50

Seminars

51

Members
Keisuke Tominaga

Director

Hitoshi Ohta

Vice-Director

Takako Miyazaki

Assistant

Kei Kita

AssistantLaser Molecular Photoscience Laboratory
Yasuhiro Kobori

Professor

Shunji Kasahara

Associate Professor

Takashi Tachikawa

Associate Professor

Masaaki Fuki

Research AssistantZhujun Zhang

Postdoctoral Fellow (~ December 2020),
Visiting Researcher (January 2021 ~)Masaaki Baba

Visiting Professor (April 2020 ~)Terahertz Molecular Chemistry Laboratory
Keisuke Tominaga

Professor

Kaoru Ohta

Research Associate Professor

Feng Zhang

Research Assistant

Masaki Okuda

Researcher

Harumi Sato

Professor (Supplementary assignment. Main assignment is Graduate Schoolof Human Development and Environment)

Yukihiro Ozaki

Visiting Professor

Terahertz Material Physics Laboratory
Hitoshi Ohta

Professor

Susumu Okubo

Associate Professor

Hideyuki Takahashi

Assistant Professor

Mitsuru Akaki

Research Assistant

Ryota Mitsumoto

Postdoctoral Fellow (March 2021 ~)Keigo Hijii

Researcher

Toshiro Kohmoto

Professor (Supplementary assignment. Main assignment is Graduate Schoolof Science)

Eiji Ohmichi

Associate Professor (Supplementary assignment. Main assignment is
Graduate School of Science)

Hikaru Kawamura

Visiting Professor (April 2020 ~)5Research Activity
I. Laser Molecular Photoscience Laboratory
I-A.

SPIN INTERACTIONS STUDIED BY TIME RESOLVED MAGNETIC RESONANCE
SPECTROSCOPY

In the natural photosynthesis, the organic solar cells and the photocatalysis, transient radical species or carriers
are immediately generated by the light-induced chemical reactions for the photo-energy conversion, providing
essential sources of the living energies. However, it has been unclear how those transient molecules are initiallyinteracting each other before the carrier-conductions or charge-dissociation take place. In our group, we aredeveloping experimental methodologies to determine molecular positions, orbital orientations and orbital
overlap (electronic coupling) in the initially generated radical-pairs, multiexcitons, and electron-hole pairs in
the photoactive proteins, in the solar cells, and in the photocatalysis on the basis of the transient electron
paramagnetic resonance (EPR) method. We have clarified several fundamental mechanisms of the energyconversions in semiconductor nanoparticles, singlet-fission materials and in the polymer systems.

Fast T-Type Photochromism of Colloidal Cu-

origin of the reversible photoinduced coloration is

Doped ZnS Nanocrystals

revealed to be a strong optical transition involving a

Y. Han1, M. Hamada, I. Chang2, K. Hyeon-Deuk2,

delocalized surface hole which survives over a minute

Y. Kobori, Y. Kobayashi1

after escaping from intraparticle carrier recombination

1

Ritsumeikan University

due to electron-hopping dissociation. ZnS NCs can be

2

Kyoto University

easily prepared in a water-mediated one-pot synthesis(J. Am. Chem. Soc., 2021)

and are less toxic. Therefore, they are promising forThis paper reports on durable and nearly temperature-large-scale

independent (at 298–328 K) T-type photochromism of

windows and building materials in addition tophotochromic

applications

such

as

colloidal Cu-doped ZnS nanocrystals (NCs). The color conventional photochromic applications. Moreover,of Cu-doped ZnS NC powder changes from pale

the present study demonstrates the importance ofyellow to dark gray by UV light irradiation, and theexcited carrier dynamics and trap depths, resulting incolor changes back to pale yellow on a time scale ofcoloration over minutes not only for photochromic

several tens of seconds to minutes after stopping thenanomaterials

but

also

for

variousadvancedlight irradiation, while the decoloration reaction is photofunctional materials, such as long persistentaccelerated to submillisecond in solutions. This luminescentmaterials

andphotocatalytic

decoloration reaction is much faster than those of nanomaterials.
conventional inorganic photochromic materials. The

Geometries

andTerahertz

Motions

Driving

Quintet Multiexcitons and Ultimate Triplet–Triplet

Dissociations via the
Fissions

6

Intramolecular Singlet

Y. Kobori, M. Fuki, S. Nakamura1, T. Hasobe1

simulations

1

Keio University

paramagnetic resonance spectra. We clarified that

(J. Phys. Chem. B, 2020)

terahertz molecular conformation dynamics play roles

Importance of vibronic effects has been highlighted

on the spin conversion from the singlet strongly

for the singlet-fission (SF) that converts one high- coupled

of

the

multiexcitonsenergy singlet exciton into doubled triplet excitons, as multiexcitons

5time-resolved

1

(TT)

to

the

electronquintet(TT) and on the intramolecularstrongly coupled multiexcitons. However, molecular

decouplings in the 6J to form spin correlated triplet

mechanisms of spin conversion processes and ultimate

pairs (T+T). The strongly coupled 5(TT) multiexcitonsdecouplings

in

the

multiexcitons

arepoorly are revealed to possess entirely planar conformations

understood. We have analyzed geometries andstabilized by mutually delocalized spin distributions,exchange couplings (singlet–quintet energy gaps: 6J)

while the intramolecular decoupled spin-correlatedof the photoinduced multiexcitons in the pentacene

triplet pairs generated at 1 μs are also stabilized bydimers bridged by a phenylene at ortho and meta

distorted conformations resulting in two separately

positions [denoted as o-(Pc)2 and m-(Pc)2] bylocalized biradical characters.

Photon-to-Energy

Mechanisms

intermediate states to characterize the geometries,

Revealed by Quantum Effects on Electron Spinelectronic couplings of spin-correlated paramagnetic

Polarization

pairs by determinations and extractions of theY. Koborianisotropic magnetic interactions and the exchange-(The Japanese Photochemistry Association Award

couplings including the SF systems [1,3]. In particular,

2019 Lecture, Invited)a novel tool of mapping the ESPs to space directions

Despiteimportance

Conversionofelucidating

generation[2,4] has been demonstrated to be powerful formechanisms of photoinduced excitons and charges forunderstanding how several nuclear motions contributedevelopments of the efficient photon-to-energy to the intermediate geometries and their mobilities forconversion systems, it has been quite difficult tocharacterizemolecular

geometries,

light-induced primary energy conversion processes

electronic (Fig. 1). [1-3]couplings and the mobilities at the photoinduced initial

It has been desired to understand the primarycharge-separations (CS) and the singlet-fissions (SF)photon-to-energy conversions processes in the plant

for heterogeneous molecular environments in protein photosynthesis, OSC thin films and the artificial
complexes, bulk heterojunction (BHJ) interfaces photosynthesis for developments of the nextbetween the electron donor acceptor domains in thegeneration devises that enable us to convert the solar

photoactive layers of the organic solar cells (OSC),

energies to the chemical reactions more efficiently. For

and in the disordered thin films. We have employed the these, it is important to elucidate the roles played bytime-resolved

electronparamagnetic

resonancemolecular geometries and motions on the electronic(TREPR) methods to characterize several electroninteractions of photoinduced primary processes in CS

spin polarizations (ESP) [1-14] of the photoinduced and the singlet-fissions (SF) in several organic systems.

7

In 1987, Closs, Forbes and Norris proposed amechanism to interpret antiphase TREPR spectra
generated in radical pairs by photoreactions in
confined molecular systems; i.e. the spin correlated
radical pair (SCRP) model. (J. Phys. Chem. 1987, 91,
3592.) Since then, the SCRP models have long beenutilized on several reaction systems in biology and inmaterial science to interpret the magnetic interactions
and dynamics of the key intermediates.
We have extended the SCRP model to therigorous scientific analysis tools establishing the

Figure 1. Geometries of the intermediate CS states inplant PSII membrane [4] in a), and OCS [2] in b), andthemultiexcitons [1] inc) asrevealed byelectron spin polarization transfer (ESPT) mechanism characterizing the anisotropic ESP by using theincluding the spin coherences and decoherences TREPR method.
through spin-polarized higher spin-multiplicities in awide variety of systems [1,2,10,11,13]. This ESPT References：model has strong impact to distinguish the anisotropic[1] S. Matsuda, S. Oyama, Y. Kobori, Chem. Sci. 2020,

and isotropic effects on ESP mainly by the11, 2934.

combinations of magnetophotoselection detections[2] Y. Kobori, T. Ako, S. Oyama, T. Tachikawa, K.

with which the polarized excitation lights are utilized

Marumoto. J. Phys. Chem. C 2019, 123, 13472.

to unambiguously determine the molecular geometries[3] Y. Matsui, S. Kawaoka, H. Nagashima, T.

and the electronic couplings in the reaction

Nakagawa, N. Okamura, T. Ogaki, E. Ohta, S.

intermediates. [2,4,5,12] This enabled us for the first

Akimoto, A. Sato-Tomita, S. Yagi, Y. Kobori, H. Ikeda,

time to experimentally understand how the molecular

J. Phys. Chem. C 2019, 123, 18813.

conformations and the vibrations contribute to the[4] M. Hasegawa, H. Nagashima, R. Minobe, T.

electronic interactions on the energy conversion

Tachikawa, H. Mino, Y. Kobori, J. Phys. Chem. Lett.

processes in several environments. [1-14] Furthermore, 2017, 8, 1179.
we have achieved major breakthroughs on unveiling[5] M. Fuki, H. Murai, T. Tachikawa, Y. Kobori, J.

the reaction mechanisms by mapping the anisotropic

Phys. Chem. B 2016, 120, 4365.

ESP to all possible magnetic field directions to[6] T. Miura, R. Tao, S. Shibata, T. Umeyama, T.

highlight clear 3D-visualizations of the geometries of

Tachikawa, H. Imahori, Y. Kobori. J. Am. Chem. Soc.

the reaction intermediates even in the highly

2016, 138, 5879.

disordered and the heterogeneous environments (Fig.

[7] Y. Kobori, T. Miura, J. R. Norris, J. Phys. Chem.

1). This electron spin polarization imaging method has

Lett. 2015, 6, 113. (Perspective)

recently demonstrated impacts of both of the[8] Y. Kobori, N. Ponomarenko, J. R. Norris, J. Phys.

intramolecular high-frequency stretching vibrations

Chem. C 2015, 119, 8078.

and the phonons on the efficient electron-hole[9] T. Miura, M. Aikawa, Y. Kobori, J. Phys. Chem.

dissociations at the BHJ interfaces in OCS.[2]Lett., 2014, 5, 30.

8

[10] Y. Kobori, R. Noji, S. Tsuganezawa, J. Phys.

[12] Y. Kobori, M. Fuki J. Am. Chem. Soc. 2011, 133,

Chem. C 2013, 117, 1589.

16770.

[11] R. Carmieli, A. Smeigh, S. M. Conron, A.

[13] Y. Kobori, M. Fuki, H. Murai, J. Phys. Chem. B

Thazhathveetil, M. Fuki, Y. Kobori, F. Lewis, M.

2010, 114, 14621.

Wasielewski J. Am. Chem. Soc. 2012, 134, 11251.

[14] Y. Kobori, Y. Shibano, T. Endo, H. Tsuji, H. Murai,
K. Tamao, J. Am. Chem. Soc. 2009, 131, 1624.

I-B.

SINGLE-MOLECULE STUDIES ON PHOTO-ENERGY CONVERSION PROCESSES

To design a more efficient solar energy conversion system (light energy to electrical or chemical energy), it isimportant to reveal and understand the mechanisms of various chemical reactions at heterogeneous interfaces.
We have investigated the photochemical and photophysical processes occurring on a variety of lightenergy conversion systems such as photocatalysis and solar cells using advanced single-molecule, singleparticle spectroscopy techniques and gain new insights related to spatial and temporal heterogeneities inreactions and structures, which are always masked by ensemble averaging.

Ultra-Narrow Depletion Layers in Hematite

oxygen vacancies yield an exceedingly high carrier

Mesocrystal-Baseddensity of 4.1 × 1021 cm−3 for super bulk conductivity

Photoanodefor

Boosting

Multihole Water Oxidationin the electrode and a large proportion of ultra-narrow

Zhujun Zhang, Hiroki Nagashima and Takashi

depletion layers (<1 nm) inside the mesoporous film.

Tachikawa

The deep band bending on the surface should provide(Angew. Chem. Int. Ed., 2020)a great enough potential gradient to drive the

Photoelectrochemical (PEC) water splitting allows forseparation of photogenerated electrons and holes and,the direct conversion of solar energy to clean andthus, effectively suppress bulk recombination, as

renewable energy sources such as H2 gas, providing anevidenced by the very small internal resistances

attractive solution to energy and environmental issues.

analyzed by electrochemical impedance spectroscopy.

Hematite (α-Fe2O3) is an ideal semiconductor for solar

We further employed photoconductive atomic force

water splitting but shows low efficiency due to themicroscopy to elucidate structure-correlated electricalsignificant charge recombination. Mesocrystals (MCs)transport properties inherent in individual MC

are superstructures of combined nanoparticles withparticles with nanoscale resolution. To unravel thesame crystal orientation. In this study, Ti-modified

water

hematite MC superstructures assembled from highly

dependence of photocurrent generation from theoriented tiny nanoparticle subunits with sizes of ca. 5

optimized Ti-modified hematite MC photoanode wasnmhigheststudied. A very low activation energy (Ea = 44 meV)

photocurrent density (4.3 mA cm at 1.23 V vs. RHE)

obtained from Arrhenius-type plots of lnJ vs. 1/T,

under back illumination (Figure 1). The rich interfacial

where J is the current density, may suggest third-order-weredeveloped

toachieve

the

−2

9

oxidationmechanism,

thetemperaturelike water oxidation kinetics. Our study provides anattractive strategy based on interfacial defectengineering for improving the PEC performance of
metal oxide semiconductors.

Figure 1. Solar-driven water splitting (left) andperformance (right) of hematite photoanodes.

In Situ Exploration of the Structural Transition

imaging along with detailed structural and elemental

duringMorphologyand

Efficiency-Conserving

characterizations revealed that sudden cooperative

HalideExchangeatransitions between two light-emitting states via

onSinglePerovskite

Nanocrystal

intermediate dark states with >100 s durations during

Izuru Karimata and Takashi Tachikawa

halide exchange originate from two distinct defect-(Angew. Chem. Int. Ed., 2020)

mediated reconstruction processes with different

Metal halide perovskites (such as MAPbI3, MA =activation energies (0.072 and 0.40 eV), leading to an+

CH3NH3 ) have recently attracted much attention as

isokinetic temperature of ca. 314 K, across a solid-

light absorbers in photovoltaic cells and as promisingstate miscibility gap between the I- and Br-rich phases

materials for optoelectronic applications including

inside a single NC. Our single-particle approach forlasers and light emitting diodes. In this study,

controlling and evaluating the rate-limiting processes

transformation

halideof ion exchange on nanostructures will help toperovskite MAPbI3 nanocrystals (NCs) to green-

improve device performance and will open new

emitting MA3PbBr3 NCs was achieved without

avenues for extending the applications of halidesignificant morphological changes and loss ofperovskite NCs.

from

red-emitting

metalphotoluminescence (PL) efficiency via a controlled
halide exchange reaction. Figure 1 shows the PL
spectra of MAPbI3 NCs with a mean size of ca. 90 nm
during halide exchange with Br− using a custom-madeflow reactor. The controlled flow of octylammonium
bromide solution caused a continuous peak shift from770 nm to 620 nm accompanied by an initial increase,and a subsequent decrease in the PL intensity. After awhile, a detectable peak appeared at approximately
550 nm, and then became more intense over time andFigure 1. Halide exchange reaction on single

eventually shifted to 530 nm. In situ single-particle PL perovskite nanoparticles.

10

betweenmodified MPS particle in phosphate buffer before andMolecular Diffusivity and Reactivity in Ruthenium

after the addition of APF under 488 nm laser

Complex-Modified Mesoporous Silica

irradiation. The burst spots are likely located near the

Tatsuya Watase, Minoru Sohmiya,1 Zhujun Zhang,

center of the particle (shown as a broken circle). This

Yasuhiro Kobori and Takashi Tachikawa

result suggests that a part of the products generated

1

Seikei University

near the outer surface escaped, again supporting our(J. Phys. Chem. C, 2020)conclusion that a series of reactions take place within

Mesoporous silicas (MPSs) are widely used as hosta single particle. By combining the above methods, amaterials

molecular

positive correlation between molecular diffusivity andsorption, separation, storage, and (photo)catalysis.

reactivity was validated, suggesting the importance of

Herein, we report single-molecule, single-particle

well-ordered nanochannels with optimized poreapproaches for exploring molecular diffusion anddiameters and adequate environments for efficientphotochemical reactions in ruthenium (Ru) complex-

heterogeneous (photo)catalysis.

Unravelingfor

HiddenCorrelations

applications

involving

modified MPS particles. Single-particle fluorescencerecovery after photobleaching (FRAP) experiments
revealed that Ru complexes are mobile in MPS withdiffusion coefficients in the range of 100−102 nm2 s−1,
which vary among the particles and locations, andtheir diffusivity decreases with increasing amount of
sulfonated phenyl groups, which act as adsorption

Figure 1. Intensity trajectory observed during 488 nm

sites for positively charged Ru complexes, on the silica

laser excitation of a single Ru dye-modified MPS

surface. Next, we focused on the detection of •OH

particle in the presence of APF (left). Spatial

over single Ru dye-modified MPS particles by

distribution of the locations of fluorescein molecules

utilizing TIRF microscopy. Figure 1 shows the(right).

fluorescence images captured for a single Ru dye-I-C.

HIGH-RESOLUTION SPECTOSCOPY OF POLIATOMIC MOLECULES

Doppler-free high-resolution spectroscopy is a powerful tool for studying the structure and dynamics of excitedpolyatomic molecules in detail and unambiguously. Single-mode auto-scan laser systems for the UV-VisibleNIR region, the absolute wavenumber measurement system, and Doppler-free high-resolution spectroscopic
measurement systems have been constructed to investigate the excited molecules.
High-resolution and high-precision measurement of spectral lines enables to observe rotationallyresolved electronic transition, then it is expected to find the excited state dynamics such as internal conversion(IC), intersystem crossing (ISC), and intramolecular vibrational redistribution (IVR) through the deviations inspectral line positions, intensity anomalies, and the changes of spectral linewidth. We have observed the high-11

resolution spectrum and the Zeeman effects of the π-π* transition of several aromatic molecules such as benzene,
naphthalene, anthracene, etc. and these molecular constants were determined in high-accuracy.
Recently, we extended our observation to the molecules with large amplitude motion such as acetaldehyde
and trans-stilbene.

of

In this work, rotationally-resolved high-acetaldehyde: Torsion-inversion-rotation inter-

resolution fluorescence excitation spectra have been

action in the excited state

observed by improvement of detection efficiency,

Ultrahigh-resolution

KosukeSpectroscopy

Nakajima, Akira

Shimizu,

Shunjiinstead of enhancement of laser power by pulsed

Kasahara, Masatoshi, Misono, Masaaki Baba

amplifier. Then, the observed spectra were higher(5th Asian Workshop on Molecular Spectroscopy,

resolution than the reported spectra. The parts of2021)

observed spectra are shown in Fig. 1. The typicalAcetaldehyde is one of a prototype for study of thelinewidth of observed spectra was about 40 MHz.

methyl torsion (internal rotation), which is the

The observed spectra around 30117 cm-1 (a) andtypical large amplitude motion. According to the30380 cm-1 (b) correspond to 1400+1502 and 1400±1504

reported study, the tunneling splitting due to theband, respectively. In comparison with the torsional

torsional barrier was found. In the S1 state, thebarrier energy, the 152 vibrational level in the S1 state

aldehyde-hydrogen inversion belong to the large

is lower energy, on the other hand, 154 vibrational

amplitude motion because the planer conformationlevel is higher energy.
We are trying to analyze the observed spectrachanges to the pyramidal conformation involving the
Therefore,

based on consideration of the interaction among theacetaldehyde in the S1(nπ*) state has these two large

overall rotation and these two large amplitude

amplitude motions unlike the S0 state. These two

motions, and then determine the rotational constantlargeof the S1 state which is physically meaning.

aldehyde-hydrogen

amplitude

distortion.

motions

correspond

to

the

vibrational mode of ν15 and ν14, respectively. In the
S1 state, it is necessary to consider the interaction

References:

between the overall rotation and these two large

1) M. Noble, E. K. C. Lee, J. Chem. Phys. 81, 1632,

amplitude motions, and the rotation structure is more(1984).

complicated than in the S0 state. Several studies on2) M. Baba, I. Hanazaki, U. Nagashima, J. Chem.

S1(nπ*) ← S0 transition have been reported. The

Phys. 82, 3938, (1985).

vibronic spectra (S1(nπ*) ← S0) under jet-cooled

3) H. Liu, E. C. Lim, C. Muñoz-Caro, A. Niño, R. H.

condition were observed by Baba et al. and Noble etJudge, D. C. Moule, J. Mol. Spectrosc. 175, 172,al. [1-2]. And, rotationally resolved spectra were(1996).

observed using a pulsed amplified CW laser [3-5]4) Y.-C. Chou, C.-L. Huang, I-C. Chen, C.-K. Ni, A.

because their intensity is weak.

H. Kung, J. Chem. Phys. 115, 5089, (2001).

125) E. Jalviste, G. Berden, M. Drabbels, A. M.
Wodtke, J. Chem. Phys. 114, 8316 (2001).

(a)

Figure 1. A part of ultrahigh-resolution fluorescence
excitation spectra of acetaldehyde of S1(nπ*)←S0transition. (a)1400+1502 band. (b)1400±1504 band.
Intensity of the lower spectra (b) is 1/3 scale of thatof the upper spectra (a).
(b)

Ultrahigh-resolution

spectroscopyoftrans-

stilbene: nonplanar structure in the ground state
Akira

Shimizu,

KosukeNakajima,

resolution laser spectroscopy and theorical calculation
by Gaussian program.
High-resolution fluorescence excitation spectra

ShunjiKasahara, Naofumi Nakayama, Masatoshi, Misono, of the 000 band and several vibronic bands in S1-S0
Masaaki Babatransition of trans-stilbene have been observed by(5th Asian Workshop on Molecular Spectroscopy,

crossing a single mode UV laser beam perpendicular2021)

to a molecular beam. Figure 1 shows the observed

The photoisomerization of stilbene is an important

high-resolution spectra of 000 band of trans-stilbene

model for chemical reaction dynamics. Many groups

S1-S0 transition. Rotational structure was found in thestudied reaction dynamics of trans-stilbene in gaseous

observed spectra. However, each rotational line wasphase1)-3) by using spectroscopic techniques.

not resolved completely due to the lifetime broadening.

High-resolution spectra of trans-stilbene S1-S0transition were observed by Leo Meerts et.al3). They

The fluorescence life time of S1 state is reported as 2.7
ns1,2).

concluded the structure of trans-stilbene in S0 state is

The observed spectra of 000 band and several

planar from the obtained rotational constants. In ordervibronic bands were a-type band. For the 000 band, we

to consider the structure and potential energy surface

determined the rotational constants, linewidth andof trans-stilbene correctly, we applied the high-rotational temperature by comparison between the13observed spectrum and calculated spectrum by using
PGOPHER program. From the obtained rotational
constants and inertial defect, it was found S0 structure
is not planar. To confirm this result, we calculate themolecular structure based on DFT calculation, itsuggested phenyl rings are twisted almost 5 degree.
References：
1) T. J. Majors, U. Even, and J. Jortner, J. Chem. Phys.
81, 2330 (1984).
2) J. A. Syage, P. M. Felker, and A. H. Zewail, J. Chem. Figure 1. High-resolution spectra of trans-stilbene 000
band, a) Observed Spectrum, b) Calculated Spectrum.

Phys. 81, 4706 (1984).
3) B. B. Champagne, J. F. Pfanstiel, D. F. Plusquellic,
D. W. Pratt, W. M. van Herpen, and W. L. Meerts, J.
Phys. Chem. 94, 6 (1990).

I-D.

HIGH-RESOLUTION SPECTROSCOPY OF NO2 AND NO3 RADICAL

Nitrogen dioxide NO2 and nitrate radical NO3 have been known as an important intermediate in chemical
reaction in the atmosphere. These radicals are the prototype molecules to understand vibronic interaction as
followings; the Renner-Teller effect for NO2, and the Jahn-Teller (JT) and pseudo Jahn-Teller (PJT) effects forNO3. Optically allowed transitions have been observed as strong absorption and LIF excitation spectra by
several research groups. For NO2 radical, hyperfine splittings are observed in high-resolution spectrum, and themagnitude of the hyperfine interaction constants suggest the state mixing between the electronic excited state
and the ground state through the vibronic interaction. Recently, we reported the hyperfine-resolved highresolution spectrum NO2 A-X system for the 14500-16800 cm-1 region.

Hyperfine-resolved

laser molecular beam and an output of a single-mode dyehigh-resolution

spectroscopy of 14NO2 radical in the 15885 cm-1

laser at the right angles. We obtained the rotationalenergy region

assignments up to N′ = 11 for the Ka = 0 series andKohei Tada and Shunji Kasahara

those up to N′ = 7 for the Ka = 1 series by analyzing(J. Mol. Struct., 2020)

the observed hyperfine structures and employing theHyperfine-resolved

high-resolution

fluorescence

excitation spectrum of the 𝐴2B2 ← 𝑋2A1 transition
of

14

-1

combinationdifferences,anddeterminedthemolecular constants of the upper vibronic level. Most

NO2 radical in the 15870 – 15900 cm energyof the Fermi contact interaction constants of theregion was observed, by crossing a jet-cooled

rotational levels of the upper vibronic level was found14

to range from 0.002 cm-1 to 0.004 cm-1. The (Ka′ = 0,N′ = 3, J′ = 3.5) level was found to be strongly
perturbed, and we recognized some perturbers in thevicinity of the main rotational level. We concluded thatthe most plausible candidate of the perturbers in thisregion is the vibronic levels of the 𝐴 2B2 electronic
state.

Figure 1. The fluorescence excitation spectrum in
15870–15900 cm-1 energy region. The rotationaltemperature was estimated to 25 K.

15

II. Terahertz Molecular Chemistry Laboratory
II-A.

LIQUID DYNAMICS STUDIED BY NONLINEAR INFRARED SPECTROSCOPY

Molecular dynamics in liquids are strongly affected by the nature of intermolecular interactions. It is greatly
important to obtain the molecular description on relation between the dynamics and interactions in liquids inorder to elucidate the solvent dynamical effect on chemical reactions. In solutions, a vibrational frequency ofsolute molecule is sensitive to changes of the solvent environment. Especially, in aqueous solution, hydrogenbond making and breaking processes play an important role in the dynamics of water molecules surrounding
the solute. Fluctuations of the vibrational transition energies, which are characterized by time correlation
functions of the frequency fluctuations, are very sensitive to the dynamics of surrounding environments.
Vibrational energy relaxation is also affected by short-range solvent-oscillator interaction.
Furthermore, orientational relaxation reflects microscopic viscosity around the oscillator. In recent years,
a great deal of effort has been devoted to investigate solute-solvent interactions with infrared (IR) nonlinear
spectroscopy such as two-dimensional IR (2D-IR) spectroscopy and pump-probe spectroscopy. 2D-IR
spectroscopy is a powerful tool to obtain microscopic information in solution such as ultrafast solvent dynamics
and local structure of solvent by probing the vibrational frequency fluctuations. By polarization-sensitive pumpprobe spectroscopy in the IR region we can study vibrational energy relaxation and orientational relaxation.

9-Fluorenone

frequency (ω1) and probe frequency (ω3). The off-

Derivatives in Water Studied by Two-Dimensional

diagonal component at (ω1, ω3) = (1694 cm-1, 1709

Infrared Spectroscopycm-1) may have information about the chemical

Yuki Fujii, Kaoru Ohta, and Keisuke Tominaga

exchange process occurring between the two(Asian Spectroscopy Conference, 2020)

hydrogen-bonded complexes. Therefore, we analyzed

In this study we performed 2D-IR spectroscopic

the 2D-IR spectra to obtain dynamical information of

measurements on 9-fluorenone-4-carboxylic acid (FL-the hydrogen-bond making and breaking processes

4) and 9-fluorenone-2-carboxylic acid (FL-2) inbetween the CO group and surrounding wateraqueous solutions. By comparing the results of FL-4

molecules. Moreover, to obtain microscopic details ofand FL-2, we aim to find the relationship between

the system, we also conducted molecular dynamics

molecular structure and vibrational dynamics. The CO(MD) simulation. By analyzing the trajectories

stretching bands of FL-4 and FL-2 are reproduced byobtained by MD simulation, we found that hydrationa single Gaussian function and a sum of two Gaussian

structure around the CO group of FL-2 is largely

functions, respectively. Based on our previous work,

different from that of FL-4. Consequently, thewe assigned the higher and lower bands in the IRhydrogen bond dynamics between the CO group andspectrum of FL-2 to a complex of FL-2 and one D2O

water molecules differ between FL-2 and FL-4.

Hydrogen

Bond

Dynamicsofand a complex of FL-2 and two D2O, respectively. 2DIR measurement provides information on thecorrelation of the vibrational spectrum at the pump16

II-B.

DYNAMICS OF ELECTRONICALLY EXCITED STATE IN CONDENSED PHASES

Understanding of dynamics in the electronically excited state is a key issue to elucidate mechanisms in various
photochemical reactions in condensed phases. It is also important for designing and developing new materials
which have characteristic functions. We employ various kinds of ultrafast technique to monitor photochemicaland photophysical invents in sub-pico- to picoseconds time scales. By femtosecond fluorescence up-conversion
technique, dynamics in the electronically excited state can be observed with a time resolution up to 100 fs.
Vibrational dynamics in the electronically excited can be investigate by UV/VIS-pump IR probe technique.
Moreover, low-frequency responses by photoexcitation are investigated by UV/VIS-pump THz probe
experiment. Such responses include change of low-frequency vibrational modes induced by photoexcitationand photo-induced changes of charge carrier dynamics.

Dynamic Behavior of Photogenerated Charge
Carriersin(PC61BM) by subpicosecond time-resolved terahertz

Diketopyrrolopyrrole-Linked (THz) spectroscopy. It was found that the decay time

Tetrabenzoporphyrin-Based Bulk Heterojunction constants of time-resolved THz signal in C4-BHJ
Thin Films Probed with Time-Resolved Terahertz films are 0.5 and 14 ps with a remaining offset at 800
nm-excitation when excitation fluence was 540 μJ/cm2.

Spectroscopy
Kaoru

Ohta,

YuichiHiramatsu,

Kohtaro The time-resolved THz signals result from boundTakahashi,1 Mitsuharu Suzuki,1 Hiroko Yamada,1polaron pairs where the charge carriers are dressed

and Keisuke Tominagawith phonons rather than from the excitons. These

1

Nara Institute of Science and Technology

polaron pairs are generated by charge separation of the(J. Photochem. Photobiol., 2020)

excitons. In contrast to neat films, the amplitudes ofUnderstanding of charge carrier dynamics on a the subpicosecond-decaying components are sensitive
picosecond time scale is very important for generation

to the fluence of the pump pulse. At higher fluence,and relaxation of charge carriers in organic these amplitudes increase due to the polaron pairphotovoltaic solar cells. Here, we study the dynamics annihilation process. At lower fluence, the transfer ofofphotogenerated

chargecarriersof the charge carriers from C4-DPP-BP to PC61BM at thediketopyrrolopyrrole-linked tetrabenzoporphyrin (C4- interface was clearly observed prior to the charge
DPP-BP) bulk heterojunction (BHJ) thin films mixed carrier quenching and generation of mobile charge
with [6,6]-phenyl-C61-butyric acid methyl ester carriers is enhanced compared to that of neat films.

Charge Transfer Dynamics of 9-Arylcarbazole

Kazuya Takamoto, Yoshifumi Ueno,1 Kaoru Ohta,

Studied by Femtosecond Transient Absorption Seiji Akimoto,1 Ryosuke Matsubara,1 and Keisuke
Spectroscopy

Tominaga1

Graduation School of Science, Kobe University(Asian Spectroscopy Conference, 2020)17

Intramolecular charge transfer (ICT) in solutions is dipole moment. In the observed TA spectra of BANCC
one of the most basic reactions, and the reaction in dimethylsulfoxide (DMSO) following excitation atmechanism of ICT is influenced by not only solute- 400 nm, a band emerges at 680 nm immediately aftersolvent interactions but also geometrical change of photoexcitation, and a new band rises at 550 nm
solutemolecule.

3,6-Bis(dimethylamino)-9-(4- together with decay of the band at 680 nm. Because

cyanophenyl)carbazole (BANCC, Figure 1) consists the band at 680 nm is similar to the observed TAof an electron donor of the carbazole unit and an spectra of BAC, it is considered that the carbazole unit
acceptor of the cyanophenyl unit, which are connected is locally excited by photoexcitation followed byby a single bond. In order to elucidate the ICT reaction charge transfer to the cyanophenyl group. Furthermore,mechanism of BANCC, we performed real timea peak of the band at 550 nm shows a blue shift with aobservation of the reaction process in various organic time constant of ~3 ps, which is similar to the solvation
solvents by femtosecond transient absorption (TA) time of DMSO. The time constants of the blue shift inspectroscopy. We also performed measurements on other solvents also show values close to the solvation
3,6-bis(dimethylamino)- carbazole (BAC), a molecule times of these solvents. This suggests that the staticof the electron donor part of BANCC.

and dynamic properties of the solvent have an effect

The absorption spectra of BANCC show two on the ICT reaction.
bands at 340 nm and 390 nm with no solvent
dependence. These spectral features are the same as
those of BAC. On the other hand, the fluorescence
spectra of BANCC show a red shift as the solvent
polarity increases, while those of BAC are lesssolvent-dependent. This result suggests that the

Figure 1. Molecular structures of BANCC and BAC.

excited state of BANCC is the ICT state with a large

I-C.

MOLECULAR DYNAMICS IN THE TERAHERTZ FREQUENCY REGION IN CONDENSED
PHASES

Vibrational spectroscopy has been widely used to investigate structures, interactions and dynamics of moleculesand molecular complexes. The low-frequency region below several terahertz (THz; 1 THz = 33.3 cm-1)
corresponds to intermolecular modes of complexes and intramolecular modes with a weaker potential force
and/or larger reduced mass. Intermolecular interactions such as hydrogen bonding, van der Waals forces andcharge-transfer interactions play important roles in various chemical and biological processes. Moreover, thelow-frequency spectra also reflect molecular dynamics on a time scale from picoseconds to femtoseconds.
There has been dramatic progress in the generation and detection techniques of freely propagating THz
radiation in the past two decades. The examples of the generation technique include photoconductive switching,optical rectification, and the surface photocurrent of semiconductors. Because the pulse duration of the THz
radiation is in a sub-picosecond time region, it is possible to measure the electric field of the radiation by18

coherent detection methods, which consequently allows us to conduct THz time-domain spectroscopy (TDS).
By THz-TDS the refractive index and extinction coefficient of a medium are obtained by measuring the phaseand amplitude of the radiation. THz-TDS is an attractive method for studying dynamics in condensed phaseswith time scales of sub-picoseconds and picoseconds. We have applied THz-TDS to investigate the lowfrequency dynamics of various kinds of condensed materials, including neat liquids and mixtures of liquids,
biological polymers, and conducting polymers.

Interpretation of THz Intensities of Molecular mode-analysis methods, we decomposed each of the
Crystals:

the

Role

of

Mixingbetween three observed THz modes into a linear combination

Intermolecular and Intramolecular Vibrations
Feng

Zhang,

Houng-Wei

Wang1,

of intermolecular translation, intermolecular principle

Keisuke librations, and intramolecular vibration. In all the three

Tominaga, Michitoshi Hayashi1, Masahiko Tani2

modes, intermolecular translations make the dominant1

National Taiwan University

contributions to the vibrational energies (>96%), while

2

University of Fukui

the contributions from intramolecular vibrations are(IRMMW-THz, 2020)

generally smaller than 2%. In order to evaluate theTani and coworkers reported the THz spectra of DL- roles played by the intermolecular and intramolecularalanine, L-alanine, and D-alanine in 2005. The vibrations to the IR intensities, we calculated theracemic

andenantiomericcompounds

display contributions of each of the five forms of motions tocompletely distinct absorption features in the the Born change vectors. We found the non-ignorable
examined frequency range of 30-95 cm-1. DL-alanine roles played by the intramolecular vibrations in theshows a major peak about 42 cm-1, while D-alanine determination of IR intensities in all the three modes.
and L-alanine have two major peaks around 74 and 86 In particular, the intramolecular vibrations are the
cm-1, respectively. We calculated the THz modes for principal components of the Born charge vectors of
DL-alanine and L-alanine. All the observed THz peaks mode for the DL-alanine and L-alanine cases.
have been reproduced. Using previously developed

Determination of the Fine Structure of a Halide
PerovskiteusingHigh-resolution

3

Shizuoka University

THz (IRMMW-THz, 2020)

Spectroscopy and Solid-state Density Functional Many types of disorders exist in the crystalline states
Theoryand affect the physical and chemical properties of theFeng Zhang, Izuru Karimata1, Houng-Wei Wang2, crystals. The short-range correlations of disorder is
Takashi Tachikawa, Keisuke Tominaga, Michitoshi one of the central issues of crystallography. In our
Hayashi2, Tetsuo Sasaki3

previous studies we demonstrated a capability of THz

1

Graduate School of Science, Kobe University

spectroscopy to detect the fingerprint vibrational

2

National Taiwan University

peaks of correlated molecular arrangements at the19nano-scale level in an occupation disorder system. considered the 16 correlations patterns and show theTHz spectroscopy may have, therefore, a promising calculated normal modes. We also examined thepotential to be a critical complementary tool to the X- correlation patterns of the MAs at a larger scale by
ray and neutron diffraction methods in the structural constructing a supercell model. The model produces,
analysis of disorder. In this work, we study the fine however, additional THz peaks not observed in the
structureofthehalideperovskite

system experimental observation. We, therefore, conclude that

(CH3NH3PbBr3) where the short-range correlations of the 16 correlation possibilities have been complete forthe disordered methylammonium (MA) cations representing the primary structures of his system.
remains an open question. Since each unit cell contains Based on the above conclusion, we suggest the halide
four MA molecules and each MA has two ways of perovskites contain ferroelectric regions within theorientations, there are in total 16 correlation nano-scale.
possibilities of the MAs in one unit cell. We

Broadband dielectric spectroscopy from sub-GHz function and Lorentzian function, respectively. The
to THz frequency region on hydrated bentonite

first term is the ion conductivity term, which may be

Lou Serafin M. Lozada, Alvin Karlo G. Tapia,1 important for conducting materials. We found that two
Armida V. Gillado,1 Naoki Yamamoto,2 and Cole-Cole functions and one Loretzian function are
Keisuke Tominaga

needed to reproduce both the imaginary and real parts

1

University of the Philippines, Los Banosof the complex dielectric spectra at room temprature.

2

Jichi Medical University

There is almost no intensity in the spectra for the dry(Asian Spectroscopy Conference, 2020)

bentonite (h = 0) from sub-GHz to sub-THz. However,

Understanding how water molecules interact with one both the real and imaginary parts of the complex
another and with clay under a confined geometry at dielectric spectra increased upon hydration. The fastdifferent temperatures are key information in energy relaxation time at 293 K is close to the bulk water
storage applications and nuclear waste disposal. Here Debye relaxation time of 9.5 ps. This suggests that
we present an investigation of the dielectric response there are freely moving bulk-like water molecules thatfrom 100 MHz to 1.8 THz of sodium bentonite at may reside outside the interlayer. On the other hand,different hydration levels from 233 K to 293 K. Our the major relaxation component has a time constantprevious studies have shown that for hydrated soft that is two orders of magnitude slower corresponding
matters such as protein and lipid bilayers the dielectric to interlayer water. It is suggested that most of the
response in the frequency region from sub-GHz to confined water in bentonite is highly restricted in its
THz are due to the relaxation processes and vibrational motion.
processes, which are modeled using a Cole-Cole

20

II-D.

INTERMOLECULAR INTERACTIONS OF POLYMER STUDIED BY TERAHERTZ
SPECTROSCOPY

Low-frequency vibrational bands observed in the low-frequency Raman and terahertz (THz) spectra originate
from the higher-order structure, crystalline structure, and intermolecular interactions of polymer materials.
Therefore, THz and low-frequency Raman spectroscopy are unique techniques for analyzing higher-orderconformations and intermolecular hydrogen bonding in semi-crystalline polymers. However, the bandassignment of THz spectra of polymers has not been studied well. Therefore, it is necessary to develop bandassignment methods in order to establish THz spectroscopy as a powerful and unique method for exploring thestructure and physical properties of polymers.

Differences in Intermolecular Interactions andcoordinate tensor transfer method suggest that these

Flexibility between Poly(ethylene terephthalate) bands of PBT include the CH2 bending mode, while
and Poly(butylene terephthalate) Studied by Far- those of PET have only a small contribution from theInfrared/Terahertz and Low-Frequency Raman corresponding mode. These differences in the thermal
Spectroscopy

behavior and vibrational modes of the 113 cm−1 bands

Y. Yamamoto, H. Hoshina1, H. Satocan be possibly attributed to the difference in1Center for Advanced Photonics, RIKEN

flexibility between PET and PBT due to the different(Macromolecules, 2021)

number of CH2 groups.
In addition, these bands of PBT seem to reflect

Herein, differences in the intermolecular interactions

and flexibility between poly(ethylene terephthalate) the intermolecular C=O···H−C hydrogen bonding.
(PET) and poly(butylene terephthalate) (PBT) are Therefore, it may be concluded that the difference instudiedbyfar-infrared,

terahertz(THz),

andthe number of CH2 groups causes the difference in thelowfrequency Raman spectroscopy and quantum flexibility of the molecular chains between PBT and
chemical calculations (QCCs). Interatomic distance PET

and

the

existenceor

non-existenceofcalculations based on the reported crystal structures intermolecular C=O···H−C hydrogen bonding. It is
and natural bond orbital analysis indicate that PBT worth noting that THz and low-frequency Raman
exhibits intermolecular hydrogen bonding between a spectroscopy can clearly reveal the difference in
C=O group and a CH2 group in the adjacent molecular flexibility. It is also very likely that both the flexibility
chains, while PET does not have such hydrogen of the molecular chains and the intermolecularbonding. The results of infrared measurements also hydrogen bonding affect the difference in thesuggest that the C=O and CH2 groups of PBT are

crystallization rate between PET and PBT.

involved in intermolecular hydrogen bonding. BothPET and PBT show a THz band at around 113 cm−1and a Raman band at around 111 cm−1. These bands
indicate different thermal behaviors of PET and PBT.
The results of QCCs performed using the Cartesian21

Figure 1. FIR/THz and low-frequency Raman spectraof PBT.

Study

ofchangesinwater structure

and in SAPs, and their temperature-dependent variations

interactions among water, CH2, and COO− groups were elucidated. At a water content of approximately
during water absorption in acrylic acid-basedsuper

absorbent

spectroscopyStudy

polymersonRaman temperature was similar to that of pure water. However,using

hydration

60%, the behavior of the fractional area versus

ofsuper at a water content of approximately 40%, the behavior

absorbent polymer by low-frequency Raman was significantly different. The fraction of SHB was
spectroscopy

smaller, and the fraction of WHB was larger than that

T. Nasu, H. Satoof pure water. The difference in the CH and COO−

(Spectrochimica Acta Part A, 2020)

peak shifts of SAP, which is a result of the addition of

The interactions of acrylic acid-based super absorbent a small percentage of water, was revealed by Raman
polymers (SAPs) with water and the hydrogen spectroscopy. The position of the CH2 deformation
bonding of water within its three-dimensional network peak changed linearly. However, the position of thewere studied using Raman spectroscopy. The Raman COO− rocking peak did not change significantly up tospectra of SAP solutions suggested that both the COO− a water content of 30%, above which it exhibited aand CH2 groups of SAPs interact with water. The rapid shift to lower wavenumbers. This result indicates
Raman spectra of pure water and those of SAPs that the interactions of the CH2 and COO− groups arecontaining approximately 40, 50, and 60% water different.
exhibited a broad band corresponding to the OHstretching mode of water in the 4000 – 3000 cm−1
region. This band was separated into three components
using a curve-fitting method. The three components at
3200, 3400, and 3600 cm−1 were assigned to the OHstretching modes of strong hydrogen bonding (SHB),
weak hydrogen bonding (WHB), and dangling bond
(Dang) species of water, respectively. The fractional
areas of the three components were calculated and Figure 1. Three kinds of OH stretching modes ofcompared. The changes in the hydrogen bonding of water; SHB, WHB, and Dang in the super absorbent
water were compared with those of the water present polymer.

22

Intermolecular hydrogen bonding of polymer byof molecular chains and intermolecular hydrogenterahertz and low-frequency Raman spectroscopy

bondings between poly(ethylene terephthalate) (PET)H. Satoand poly(butylene terephthalate) (PBT), and so on.
th

(The

10

International

SymposiumonTwo- Furthermore, THz imaging was successfully used todimensional Correlation Spectroscopy (IW-FIRST visualize the distribution of crystallinity and crystal
2021))

orientation in polymer films. In the future, it is

The weak C-H···O hydrogen bonds of polymers expected that THz and low-frequency Raman
play a crucial role in stabilizing the crystalline spectroscopy will be more widely used to evaluate thelamellae and folding of the molecular chain of physical properties of polymer materials.
polymers, and it has a significant effect on the physicalproperties of the polymer. Terahertz (THz) and lowfrequency

Raman

spectroscopy

canprovideinformation on the higher-order structure andintermolecular hydrogen bonding of polymers.
Therefore, by performing FIR, THz or low-frequency
Raman spectra measurements with quantum chemical
calculations (QCCs), we have investigated the weak Figure 1. Temperature-dependent THz spectra of PCL
hydrogen bonding in the crystalline structure of in the temperature range of 35 to 65 °C, and a THz
imaging of distribution of crystallinity of PCL film.[1]polyesters.
THz and low-frequency Raman spectroscopy
successfully

detectedthedifferent

types

of [1] C. Funaki, S. Yamamoto, H. Hoshina, Y. Ozaki,

intermolecular hydrogen bonds in the lamellar and H. Sato, Polymer, 137 (2018) 245.
structure of polycaprolactone (PCL), a changing in the [2] C. Funaki, T. Toyouchi, H. Hoshina, Y. Ozaki, andinter-

andintramolecularhydrogenbonds

of H. Sato, Applied Spectroscopy, 71 (2017) 1537.

polybutylene succinate (PBS) by stress-induced [3] Y. Yamamoto, H. Hoshina, and H. Sato,crystal transition, and the differences in the mobility Macromolecules, in press (2021).

23

III Terahertz Material Physics Laboratory
III-A.

HIGH FIELD ELECTRON SPIN RESONANCE (ESR) STUDIES OF QUANTUM SPINSYSTEMS

The quantum effects and the spin frustration effects prevent long-range order due to strong quantum
fluctuation and frustration. Their ground states at low temperature are attractive issue in field of solid statephysics. High-frequency high-field ESR is a powerful spectroscopic method to investigate the ground stateand lower excited state of the system, because the ESR observes directly the magnetic excitation. Following
the trends from a Grant-in-Aid for Scientific Research on Priority Areas “Novel states of matter induced byfrustration” (No.473, 2007-2011, Headed by Prof. H. Kawamura (Osaka University) and H. Ohta was amember), we are studying these low dimensional antiferromagnets with frustration and related multiferroic
materials intensively. Appearance of breather, soliton and antisoliton modes are expected in wide frequencyfield ESR measurements of S = 1/2 Heisenberg antiferromagnetic chain with staggered D vector system
KCuMoO4(OH). We succeeded in observing these signals using micro-single-crystal of KCuMoO4(OH). The
magnetic anisotropy of breather excitations, soliton and antisoliton modes have been revealed. Following
researches have been also performed by the joint research program of Molecular Photoscience ResearchCenter, Kobe University. We continued collaborations with H. Kikuchi's group in University of Fukui for
quantum spin systems. Exotic Co system CoSeO3 has fruitful magnetic phases. High field ESR and magnetic
torque measurements of CoSeO3 revealed anomalous spin reorientations under magnetic fields. For otherjoint researches, high-field ESR and the magnetic susceptibility measurements of thin film of neodymium
permanent magnets have been performed to obtain information of the magnetic anisotropy. And we also havejoint research with theoretical groups for obtaining experimental parameter from quantum calculations. In
total, our joint researches have been performed with 19 groups, and we have organized one scientific meetingwith joint research groups.
H. Ohta is continuing as the Immediate-Past President of IES (2018-2020) after finishing the President(2015-2017) of the International EPR (ESR) Society (IES). H. Ohta is also acting as the Advisory Council of
APES (Asia-Pacific EPR/ESR Society), and the Council Member of the Society of Electron Spin Scienceand Technology (SEST). H. Ohta is the Local Organizing Committee Chair and S. Okubo is the member ofthe fund-raising committee of the ISMAR-APNMR2021 which will be held in Aug., 2021 as the on-line
conference.
Moreover, in order to strengthen the pulsed magnetic field researches in the western Japan region, we
have been continuing the activities of The KOFUC (Kobe-Osaka-Osaka Prefecture-Fukui Universities
Centers) Network since 2014.

24

Development of Eu2+ and Mn2+ co-activated silicate

We propose a pulse light source using Xe discharge.

phosphor for plant cultivation light source

For the rapid growth of the plant, an intense light1,

Yoshiko Fujita1, Hiroshi

covering the absorption spectral region of chlorophyll

Kajiyama1, Tetsuo Honma2, Hideki Kawaguchi3,

is demanded, and periodic irradiation is also required

Tadashi Ishigaki3, Koutoku Ohmi3, Kentaro

because the photosynthetic reaction has a certain

Ohshima4, Daisuke Miyazaki4, Yu Saito5, Shigeo

period. In this study, Sr3MgSi2O8:Eu, Mn phosphor

Hara5, Takahiro Sakurai5, Susumu Okubo6, andpowders with various Eu and Mn content, which show

Hitoshi Ohta4,6

two emission peaks in the absorption region of1

Department of Nano Material and Bio Engineering,

photosynthetic pigment and phytochrome, were

Tokushima Bunri University

synthesized,

2

Japan Synchrotron Radiation Research Institutediffraction, photoluminescence and electron spin

3

Graduate School of Engineering, Tottori University

resonance spectroscopy. It was found that the4

Graduate School of Science, Kobe University

exchange-coupled Mn-Mn and Eu-Mn pairs lead the5

Research Facility Center for Science and Technology, rapid decay of Mn emission and efficient energy

Takashi Kunimoto

and

were

analyzed

using

X-ray

Kobe University

transfer from Eu and Mn ions, respectively. A plasma

6

Molecular Photoscience Research Center, Kobe

tube array panel using the phosphor was also

University

fabricated and the similar emission spectrum of(Jpn. J. Appl. Phys., 2019)

Sr3MgSi2O8:Eu,Mn is obtained under vacuum-UV

Various light sources for plant production have been

excitation in comparison to the UV excitation.

developed to establish a completely controlled factory.

II-B.

DEVELOPMENT OF NOVEL ESR TECHNIQUES IN THE THz REGION USINGMICROMECHANICAL DEVICES

Force detection of ESR signal is a powerful tool in sensitive detection of small-volume samples. In thistechnique, sample magnetization changes accompanied by ESR absorption are converted to a field-gradient
force exerted on a SiNx nanomembrane. The force-detected ESR technique using a 10 T split-pairsuperconducting magnet was newly developed. We applied this technique to non-centrosymmetric magnet
CuB2O4, and revealed from the angle-dependent ESR measurement that the ESR signals observed in theordered phase are attributable to paramagnetic resonance, rather than antiferromagnetic resonance.
Another promising application of force-detected ESR is metalloprotein. However, the low spin
concentration generally makes ESR detection of these samples quite difficult. To solve this problem, we
combined our technique with high-power terahertz source, gyrotoron, installed at Fukui University, andsuccessfully improved the detection sensitivity. Measurements were carried out at Fukui University withhelps of Dr. Ishikawa and Prof. Mitsudo. ESR signals of DPPH and CuPzN were observed at room
temperature. In the future, this technique will be applied to hemoproteins.

25We also developed a novel high-frequency ESR technique exploiting thermal process accompaniedwith ESR absorption. With a sample attached at the end of cantilever beam, temperature at the beam end
increases due to thermal relaxation when the ESR condition is met. The resultant temperature gradient issensitively measured using a thermocouple. The advantages are high sensitivity, small background, and wide
temperature range. We succeeded in multi-frequency ESR measurement of DPPH at various temperatures.
Practical applications to various magnetic samples will be promising in the near future.
Collaborative research with Dr. Horitani at Saga University was also carried out. ESR signals of modelcompounds were observed, but further sensitivity improvement is needed for more detailed analysis. H.
Takahashi also conducted the research project from JST-PRESTO's program "Thermal Science and Controlof Spectral Energy Transport", in which the heat transport of magnetic materials was studied by highfrequency ESR spectroscopy.
Prof. Ohta gave invited talks regarding nanomembrane-based ESR in the terahertz region at “Modern
Development of Magnetic Resonance” and “International Conference on Infrared, Millimeter, and Terahertz
Waves (IRMMW-THz 2020)”. H. Takahashi gave an invited talk at “The 8th International Workshop on FarInfrared Technologies (IW-FIRT 2021)”.

Zero ‐ Field Splitting Parameters of Hemin

hemin is known as a model substance of hemoproteins,

Investigated by High ‐ Frequency and High ‐the pressure effect on the electronic structure has not

Pressure

yet been explored owing to the large ZFS. In this study,

Electron

Paramagnetic

Resonance

Spectroscopy

high-field and high-frequency EPR measurements

E. Ohmichi1, T. Okamoto1, T. Sakurai2, H.

were carried out in the frequency range up to 700 GHz

Takahashi3, S. Okubo3, H. Ohta3

and at hydrostatic pressures up to 2 GPa. At ambient

1

Graduate School of Science, Kobe University

pressure, multiple EPR branches were clearly2

Research Facility Center for Science and Technology, observed, and the axial and rhombic components ofKobe University

ZFS were determined as 𝐷 = 6.90±0.01 cm−1 and3

Molecular Photoscience Research Center, Kobe

= 0.055±0.005 cm − 1, respectively. Upon pressure

University

application, we observed a systematic shift of the(Appl. Mag. Res., 2020)

resonance field, indicating a monotonous increase of

We systematically studied the zero-field splitting

the axial component from D = 6.9 to 7.9 cm−1at 2 GPa.

(ZFS) parameters of Fe(III) protoporphyrin IX

The origin of this unusually large shift was discussed

chloride, or hemin, using the terahertz electronfrom a microscopic viewpoint of the electronicparamagnetic

structure of iron under pressure.

resonance(EPR)

spectroscopy

technique at ambient and high pressures. Although

26

𝐸Mechanically Detected Terahertz Electron Spindescribed to demonstrate its usability as a novel

Resonance

methodology for obtaining microscopic insights into

E. Ohmichi1, T. Okamoto1, H. Takahashi2, H.

local electronic structures. Using micromechanicalOhta2

devices, the sensitivity to a small-volume sample is1

Graduate School of Science, Kobe University

greatly enhanced even for a cavityless setup.

2

Molecular Photoscience Research Center, Kobe

Moreover, there are plenty of options in the setup of

University

MDESR, including detection modes, mechanical(Appl. Mag. Res., 2021)

devices, and detection techniques. ESR spectroscopy

In this review, mechanically detected electron spinof single-crystalline, powder, and frozen solution

resonance (MDESR) in the terahertz (THz) region is

samples in the THz region are demonstrated.

Force detection of high-frequency electron spin

We report the measurement of force-detected electron

resonance near room temperature using high-spin resonance (FDESR) at 154 GHz using a gyrotron.

power millimeter-wave source gyrotron

The high output power allows the use of a strong

H. Takahashi1, Y. Ishikawa2, T. Okamoto3, D.

transverse magnetic field larger than 10−4 T, which is

Hachiya3, K. Dono2, K. Hayashi2, T. Asano4, S.

sufficient to cause ESR saturation. We obtained the

Mitsudo2, E. Ohmichi3, and H. Ohta1

FDESR signal with a high spin sensitivity on the order1

Molecular Photoscience Research Center, Kobeof 1012 spins/G at 280 K. Our system has promising

University

applications in high-frequency ESR studies of low-2

Research Center for Development of Far-Infrared

spin concentration samples, such as metalloprotein

Region, University of Fukui

solutions.

3

Graduate School of Science, Kobe University

4

Department of Applied Physics, University of Fukui

This study was partially supported by the
Murata Science Foundation.

(Appl. Phys. Lett.,2021)

III-C.

DEVELOPMENT AND APPLICATION OF HIGH-PRESSURE THz ESR SYSTEMHigh pressure THz ESR is a very powerful means to clarify the pressure effect of magnetic materials. Oneof the features of our high pressure ESR system is the use of a piston-cylinder pressure cell which has both
good transmittance of electromagnetic wave in THz region and a maximum pressure of 2.5 GPa. However,there remained a problem in accurate pressure calibration for this system. Therefore, we have developed a
new system with induction coils outside the pressure cell, which enable AC magnetization measurement oftin set inside the pressure cell. The superconducting transition temperature of tin depends the pressure andthe relationship can be used for pressure calibration. This system enables accurate pressure calibration in
addition to the conventional transmission-type ESR measurement for a sample set in the pressure cell.
Furthermore, we manufactured a new cylinder with a slightly smaller inner diameter than the previous one
27and succeeded in expanding the pressure range to 2.8 GPa. Using this system, a typical paramagnet cobalt
Tutton's salt was measured, and the g principal values were determined at 0 GPa for the first time. Owing to
the high spectral resolution of this system, the in-plane anisotropy was observed in the cobalt Tutton's salt,
which was believed to have uniaxial anisotropy. Moreover, it was found that the g principal values change
significantly with pressure. A master course student M. Yasutani received the poster award at the 29th Japan
Society of Infrared Science and Technology annual meeting (29-30 October, online) on his development of
this high-pressure ESR system and its application.
In addition, the thermal detection type ESR was applied to the high pressure ESR measurement. A
thermocouple was introduced into the pressure cell, and the ESR signal of the cobalt Tutton's salt was
successfully detected as the temperature increase during resonance. We also succeeded in combining thedeveloped probe with the split-pair magnets and obtaining the angle dependence of ESR signal of the cobalt
Tutton's salt.
H. Ohta gave invited talks at Modern Development of Magnetic Resonance, and International
Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2020) on the development of highpressure THz ESR system and its application. T. Sakurai gave an invited talk at “International Workshop on
Quantum Magnets in Extreme Conditions” especially on the application to the orthogonal dimer-spin system
SrCu2(BO3)2 (2021.3.22-26, online).

Pressure control of the magnetic anisotropy of the(Phys. Rev. B, 2021)

quasi-two-dimensional van der Waals ferromagnet

We report the results of the pressure-dependent

Cr2Ge2Te6

measurements of the static magnetization and of theT. Sakurai1, B. Rubrecht2,3, L. T. Corredor2, R.

ferromagnetic resonance (FMR) of Cr2Ge2Te6 toTakehara4,

A.

address the properties of the ferromagnetic phase of

Alfonsov2, S. Selter2,3, S. Aswartham2, A. U. B.

this quasi-two-dimensional van der Waals magnet.

Wolter2, B. Büchner2,5, H. Ohta6, and V. Kataev2

The static magnetic data at hydrostatic pressures up to

1

M.

Yasutani4,J.

Zeisner2,3,

Research Facility Center for Science and Technology, 3.4

GPa

reveala

gradualsuppressionofKobe University

ferromagnetism in terms of a reduction of the critical2

Leibniz IFW Dresdentransition temperature, a broadening of the transition

3

Institute for Solid State and Materials Physics, TU

width, and an increase of the field necessary to fully

Dresdensaturate the magnetization Ms. The value of Ms ≃4

Graduate School of Science, Kobe University

3μB/Cr remains constant within the error bars up to a5

Institute for Solid State and Materials Physics andpressure of 2.8 GPa. The anisotropy of the FMR signal

Würzburg-Dresden Cluster of Excellence ct.qmat, TU

continuously diminishes in the studied hydrostatic

Dresdenpressure range up to 2.39 GPa, suggesting a reduction

6

Molecular Photoscience Research Center, Kobeof the easy-axis-type magnetocrystalline anisotropy

University

energy (MAE). A quantitative analysis of the FMR
28data gives evidence that up to this pressure the MAE

higher pressures, if possible at all, due to the observed

constant KU, although getting significantly smaller,

weakening of the ferromagnetism under pressure. This

still remains finite and positive, i.e., of the easy-axis

circumstance may be of relevance for the design oftype. Therefore, a recently discussed possibility ofstrain-engineered

switchingcontaining layers of Cr2Ge2Te6.

the

sign

of

the

magnetocrystalline

functional

heterostructures

anisotropy in Cr2Ge2Te6 could only be expected at still

III-D.

MAGNETIZATION MEASUREMENTS USING SQUID MAGNETOMETER

The installation of SQUID magnetometer in 2010 by a Grant-in-Aid Creative Scientific Research“Development of properties and functionalities by precise control of rare-earth doping” (2007-2011, Prof. Y.
Fujiwara (Osaka University) opened up wide varieties of collaborative researches. From 2010 applicationsof SQUID magnetometer to various material researches spread out continuously. It is also supporting theuser programs of Molecular Photoscience Research Center, Kobe University since 2017. Users of SQUID
magnetometer are Mochida and Takahashi group, Uchino group (Department of Chemistry, Kobe University),
Sugawara and Matsuoka group, and Kotegawa and Tou group (Department of Physics, Kobe University), T.
Sakurai, S. Hara and Y. Saito (Center for Supports to Research and Education Activities, Kobe University).

Magnetic and Transport Properties of New Cubic

Kondo-latticecompound

with

the

transition

compounds Ce6Pd13Cd4 and R6Pd13Zn4 (R = Pr,temperature at TN = 2.9 K. The increase in theNd) with the Octahedral Rare-Earth Sublattices

magnetic susceptibility below TN and the large value

Eiichi Matsuoka1, Yasuo Iwakiri1, Akihiro Oshima1, of the specific heat divided by temperature (1.47 J/CeHitoshi Sugawara1, Takahiro Sakurai2, and Hitoshi

mol K2) imply the existence of non-ordered Ce

Ohta3

magnetic moment due to the geometrical frustration

1

Department of Physics, Graduate School of Science,on the octahedral Ce sublattice. No magnetic transition

Kobe University

has been detected for Pr6Pd13Zn4 above 0.62 K, while2

Research Facility Center for Science and Technology,

phase transition which is presumably due toKobe University

antiferromagnetic order has been observed for3

Molecular Photoscience Research Center, Kobe

Nd6Pd13Zn4 at Tt = 1.2 K. The large values of the

University

paramagnetic Curie temperature divided by transition(JPS Conf. Proc., 2019)

temperature (>13.2 for Pr6Pd13Zn4 and 5.1 for

Magnetic and transport properties of the cubic

Nd6Pd13Zn4) suggest that the magnetic transition

compounds Ce6Pd13Cd4, Pr6Pd13Zn4, and Nd6Pd13Zn4

temperatures

have been investigated by the magnetization, thegeometrical frustration on the octahedral rare-earths

electricalsublattice.

resistivity,

and

the

specific-heatmeasurements. Ce6Pd13Cd4 is an antiferromagnetic
29

arestrongly

suppressed

by

the

Magnetic, Transport, and Thermal Properties ofan octahedral sublattice. In this study, we have grown

New Cubic Compounds Ce6Mg23Z (Z = C, Si, Ge)

polycrystalline samples of Ce6Mg23Z and studied their

Shibuya1,

Matsuoka1,

Hitoshimagnetic and transport properties. We found that the

Sugawara1, Takahiro Sakurai2, and Hitoshi Ohta3

Ce ions in these compounds are trivalent and1

Department of physics, Graduate School of Science,

antiferromagnetic transition occurs at 1.6 and 1.2 K

Kobe University

for Ce6Mg23Ge and Ce6Mg23Si, respectively. The large

2

Research Facility Center for Science and Technology,

values of the paramagnetic Curie temperature divided

Kobe University

by the antiferromagnetic transition temperature (4.5

3

Molecular Photoscience Research Center, Kobe

for Ce6Mg23Ge and 9.9 for Ce6Mg23Si) imply

University

suppression(JPS Conf. Proc., 2019)geometrical frustration on the octahedral Ce sublattice.

Ryota

Eiichioftransition

temperature

due

to

We have focused on new cubic compounds Ce6Mg23Z(Z = C, Si, Ge) in which Ce atoms are reported to form

Proximity coupling of superconducting nanograins

7with fractal distributions

Accelerator Research Organization

Takashi Uchino1, Nanami Teramachi1, Ryosuke

8

Matsuzaki1, Emi Tsushima1, Shusuke Fujii1,

Activities, Kobe University

Yusuke Seto2, Kazuyuki Takahashi1, Takao Mori3,

9

Yutaka Adachi4, Yukihito Nagashima5, Yoshifumi

University

Sakaguchi6, Kazuki Ohishi6, Akihiro Koda7,(Phys. Rev. B, 2020)

Takahiro Sakurai8 and Hitoshi Ohta9

We explore the electrical and magnetic properties of a1

Department of Chemistry, Graduate School offractal assembly of Josephson junctions with

Science, Kobe University

transparent interfaces. For this purpose, we employ an

2

Department of Planetology, Graduate School of

Mg/MgO/MgB2 nanocomposite with ∼16 vol. % of

Science, Kobe University

MgB2 nanograins, which are distributed in a fractal

3

Center for Support to Research and Education
Molecular Photoscience Research Center, Kobe

International Center for Materials Nanoarchitectonics, manner in the normal matrix. Irrespective of the low

National Institute for Materials Science
4

Institute of Materials Structure Science, High Energy

Optoelectonic

Materials

Group,

volumeOpticalfractionof

MgB2

nanograins,

the

and

nanocomposite behaves as a bulk-like superconductor,

Electronic Materials Unit, National Institute fori.e., zero resistivity, perfect diamagnetism, and strong

Materials Science

vortex pinning. Thus, a global Josephson phase5

Nippon Sheet Glass Co., LTDcoherence is achieved in the nanocomposite. The

6

Neutron

ScienceandTechnology

Center,lower (Hc1J ) and higher (Hc2J ) critical fields of theComprehensive Research Organization for Science

Josephson network are exceptionally high (Hc1J = 96

and Society (CROSS)

Oe and Hc2J = 83.5 kOe) as compared to those reported30

previously for granular superconductors. This will

increases with decreasing temperature below whichgive

macroscopic

the Josephson phase coherence sets in, opposite to thesuperconducting coherence derived from long-range

diamagnetic response observed in magnetization

anexampleofrobustproximity coupling among fractally distributed measurements. This unusual behavior implies a highly
superconducting

nanograins

throughquantum

disordered and fluctuating nature of the Josephson

interference of Andreev quasiparticles. Transverse-

vortices

field muon spin rotation measurements reveal that thenanocomposite.

in

the

present

superconducting

mean internal field in the superconducting mixed state

The

Impactofthe

Next-Nearest

Neighbor analysis of 1 revealed that the Fe(III) complex
Crossovermolecules formed a three-dimensional π-stacking

Transition Enthalpy Evidenced by Experimental

interaction network. To thermodynamically clarify theand Computational Analyses of Neutral π-mechanism of the SCO transition, the thermodynamic

Extended Heteroleptic Fe(III) Complexes

parameters of the SCO transitions for 1 and 2 were

A. Miyawaki1, T. Mochida1,2, T. Sakurai3, H. Ohta4,

deduced from the temperature dependence of theand K. Takahashi1

magnetic susceptibility in the solid and solution states

1

Department of Chemistry, Graduate School ofusing the regular solution model. A comparison of the

Science, Kobe University

SCO enthalpy difference between the solid and2Center for Membrane and Film Technology, Kobe

molecule for 1 and 2 revealed that the lattice enthalpy

University

difference would largely contribute to the SCO

3

Research Facility Center for Science and Technology,transition enthalpy difference. A computational

Kobe University

evaluation of intermolecular interactions and lattice4

Molecular Photoscience Research Center, Kobeenergies before and after the SCO transitions in 1 andDispersion

Interactions

on

Spin

University

2 disclosed the significant contribution of the next-

5

Muroran Institute of Technology

nearest neighbor dispersion interactions to the lattice6

Department of Physics, Okayama University

enthalpy differences. This finding indicates that not(Inorganic Chemistry, 2020)

only conventional nearest neighbor intermolecular

A neutral heteroleptic Fe(III) complex 1 derived frominteractions but also next-nearest neighbor dispersion

a π-extension of the parent complex 2 was preparedinteractions should be taken into account toand characterized. Complex 1 exhibited an abrupt spin

understand the fundamental mechanism of a phasecrossovertransition in molecular solids.

(SCO)

transition

exactlyatroom

temperature (TSCO = 298 K). A crystal structure

Synthesis, Structure, and Magnetic Properties ofPorphyrin Analogues Embedded with Binaphthol

Linear Trinuclear CuII and NiII complexes of

Units
31

J. Setsune1, S. Omae1, Y. Tsujimura1, T. Mochida1,

sites. In fact, a CuII3 complex with a Cu(1)–Cu(2)T. Sakurai2 and H. Ohta3

distance of 2.910 Å, a Cu(1)–Cu(2)–Cu(1′) angle of1

Department of Chemistry, Graduate School of

174.7°, and a very planar Cu2O2 diamond core was

Science, Kobe University

obtained. The variable-temperature 1H-NMR study of2

Research Facility Center for Science and Technology,

the CuII3 complex showed increasing paramagnetic

Kobe University

shifts for the naphthyl protons as temperature3

Molecular Photoscience Research Center, Kobe

increased, which suggests strong antiferromagnetic

University

coupling of CuII ions. The temperature dependence of(Symmetry, 2020)

themagnetic

susceptibility

indicatedII

A porphyrin analogue embedded with (S)-1,1′X-bi-

antiferromagnetic coupling both for the Cu 3 complex

2-naphthol units was synthesized without reducing(J = −434 cm−1) and for the NiII3 complex (J = −49

optical purity of the original binaphthol unit. This new

cm − 1). The linear (L)M(µ-OR)2M(µ-OR)2M(L) coremacrocyclic ligand provides the hexaanionic N4O4

in a rigid macrocycle cavity made of aromaticcoordination environment that enables a linear array ofcomponents provides robust metal complexes thatthree metal ions. That is, it provides the square planar

undergo reversible ligation at the apical sites of theO4 donor set for the central metal site and the distorted

central metal.

square planar N2O2 donor set for the terminal metal

Nonmagnetic first-order phase transition in the

We report the discovery of a first-order phasenonsymmorphic NbCrP

transition at around 125 K in NbCrP, which is the

Yoshiki Kuwata1,2, Hisashi Kotegawa1, Hideki Tou1, nonsymmorphic crystal with P nma space group. From
Harima1,

Ding2,

Keiki

the resistivity, magnetic susceptibility, and nuclear

Takeda3, Junichi Hayashi3, Eiichi Matsuoka1,

magnetic resonance measurements using crystals

Hitoshi Sugawara1, Takahiro Sakurai4, Hitoshi

made by the Sn-flux method, the high- temperature

Ohta1,5, and Yuji Furukawa2(HT) phase is characterized to be metallic with a non-1

Department of Physics, Kobe University

negligible magnetic anisotropy. The low-temperature

2

Ames laboratory, U.S. DOE and Department of(LT) phase is also found to be a nonmagnetic metallic

Hisatomo

Qing-Ping

Physics and Astronomy, Iowa State University

state with a crystal of lower symmetry. In the LT phase,3

Muroran Institute of Technology

the spin susceptibility is reduced by ∼30% from that

4

Research Facility Center for Science and Technology,

in the HT phase, suggesting that the phase transition is

Kobe University

triggered by the electronic instability. The possible

5

Molecular Photoscience Research Center, Kobe

origin of the phase transition in NbCrP is discussed

University

based on the electronic structure by comparing it with

(Phys. Rev. B, 2020)

those in other nonsymmorphic compounds RuP and
RuAs.

32

III-E.

DEVELOPMENT OF NEW MICROWAVE SPECTROSCOPY TECHNIQUESThe dynamics of superconducting vortices in unconventional superconductors is expected to have different
characteristics from those in conventional superconductors. In particular, the Hall effect caused by flux flow
is interesting because it provides us insights into the quasiparticle states inside the vortex core. However, its
observation requires electromagnetic waves with frequencies higher than microwaves to eliminate the effectof vortex pinning. Takahashi developed a microwave Hall effect measurement method using a cross-shaped
bimodal microwave resonator with Professor Maeda's group at the University of Tokyo.

Microwave Hall effect measurement for materials

property is represented by the surface impedancein the skin depth region

tensor; furthermore, we constructed the method to

Ryo Ogawa1, Tatsunori Okada2,

Hideyukiobtain the Hall component of the surface impedance

Takahashi3, Fuyuki Nabeshima1 and Atsutaka

tensor in terms of the change in resonance

Maeda1characteristics. To confirm the validity of the new

1

Department of Basic Science, The University ofmethod, we applied our method to measure the HallTokyo

effect in metallic Bi single crystals at low temperatures,

2Institute for Materials Research, Tohoku University,and we confirmed that the microwave Hall angles

3

Molecular Photoscience Research Center, Kobe

coincide with the DC Hall angle. Thus, it becomes

University

clear that the Hall angle measurement under cryogenic(J. Appl. Phys., 2021)

conditions becomes possible without any complicatedWe developed a new microwave Hall effecttuning mechanisms, and our bimodal cavity methodmeasurement method for materials in the skin depth

can be used to measure the microwave Hall effect onregion at low temperatures using a cross-shapedmaterials in the skin depth region. The result opens abimodalcalculated

new approach to discuss the Hall effect in condensed

electromagnetic fields in the cross-shaped cavity andmatter physics such as the microwave flux-flow Hall

the response of the cavity including the sample, whose

effect in superconductors.

III-F.

cavity.

We

analytically

SPIN AND LATTICE DYNAMICS STUDIED BY PUMP-PROBE AND TERAHERTZ
SPECTROSCOPIESThe terahertz region in the electromagnetic spectrum has attracted research attention in solid-state physics,
because elementary excitations in solid-state materials such as phonons and magnons play important roles, andmany of those dynamics appear in this energy region. The ultrafast spin dynamics and optical spin control inmagnetic materials are attractive topics because of the potential applications in the developments of ultrafast
spin control, spintronics, quantum computing, and optical control of correlated spin systems. We studied thespin and lattice dynamics in solid-state materials using optical pump-probe spectroscopy and terahertz time33

domain spectroscopy (THz-TDS). The generation and detection of magnetization and birefringence using
optical and electric pulses are very useful to observe the spin and lattice dynamics in ferromagnetic,
antiferromagnetic, multiferroic, and magnetoelectric materials. The time-domain spectroscopy has a large
potential for the ultrafast, broadband, and accurate observation of elementary excitation dynamics in theterahertz region.

Terahertz

time-domain

spectroscopy

inthe time domain by THz-TDS using broadband THz

antiferromagnetic cobalt oxide

waves. In the experiment, CoO samples with (100)Y. Iwasaki1, M. Kita1, Y. Kokogawa1, T. Moriyasu2,plane orientation and the thickness of 0.1, 0.5, 0.9, andand T. Kohmoto1,3

3.0 mm were used.

1

Graduate School of Science, Kobe University

2

University of Fukui

electric field observed at 5 K, it is confirmed that the3

Molecular Photoscience Research Center, Kobe

0.9-mm CoO has a slight dip near 4.5 THz. It is found

Universitythat the spectral amplitude above 4 THz is(iCAMP 2020)

considerably reduced in the 3.0-mm CoO. It is

The absorption of the 4.4-THz magnon mode in cobalt

considered that this is because the absorption in theoxide (CoO), which is antiferromagnetic below thehigher frequency region increases as the thickness

Néel temperature (TN = 290 K), was observed byincreases, due to the influence of the phonon-

terahertz time-domain spectroscopy (THz-TDS) using

absorption tail of CoO that has a peak on the higher

air plasma.

frequency side.

From the Fourier spectra of the transmitted THz

Magnons are magnetic elementary excitations

From the temperature dependence of thein magnetic materials, which are quantized spin waves. normalized transmission spectrum of the THz electric
At room temperature, CoO has a rock-salt type cubic

field observed in the 0.9-mm CoO, it is confirmed thatcrystal structure and is paramagnetic, while, below TN,

there is a dip near 4.4 THz at 5 K and 50 K, but the dip

it has a tetragonal crystal

and isdisappears at the temperature of 100 K or higher. It is

antiferromagnetic (AFM). In the AFM phase, cobalt

thought that this is because the influence of the tail ofspins align ferromagnetically within a (111) plane, andthe phonon absorption increases as the temperaturethese planes are stacked antiferromagnetically in theincreases, the spectral amplitude of the high-frequency

direction normal to (111) planes. In the present study,

components decreases, and the absorption of magnon

we attempted to observe magnon absorption of CoO in

becames invisible.

Lattice dynamics in an antiferromagnet chromium

1

Graduate School of Science, Kobe University

oxide

2

Molecular Photoscience Research Center, Kobe

Y. Maeda1, S. Kawabata1, H. Taniguchi1, R. Hikita

University

1, and T. Kohmoto1,2(iCAMP 2020)

structure34

In recent years, various types of multiferroic materials,

applied, the oscillation frequency does not change.

in which ferroelectric and magnetic orders coexist,

This shows that the observed damped oscillation ishave been found. Many of them are antiferromagnets

considered to be a lattice vibration.

which have spin structures of spiral type, and their

The optically induced ellipticity signals for the

giant magnetoelectric effect has been attracting

pump of 900 nm decay exponentially in theattention. Antiferromagnetic chromium oxide (Cr2O3,

nanosecond region. The signals were fitted using a

Néel temperature TN = 307 K) is not multiferroic, but

single-exponential fitting function, and the relaxation

has been interested in its magnetoelectric effect.

time was obtained. In some temperature regions, theIn the present study, we pay attention to the single-exponential fitting does not work. A doublerelation between spin and lattice in Cr2O3 and studied

exponential fitting function was used to fit the two

the optically induced lattice dynamics using the pump-components, and the slow and fast relaxation times

probe technique. The pump pulse (0.2 ps, 1300 or 900 were obtained.
nm) and the probe pulse (0.2 ps, 800nm) are linearly

It was found that the relaxation rate of the slow

polarized and collinear. The sample is excited by thecomponent diverges toward the antiferromagnetic

pump pulse. The rotation of the polarization planetransition temperature (TN = 307 K). Generally, there(rotation signal) and the ellipticity (ellipticity signal) is no correlation between the lattice and spin, but thisof the transmitted probe pulse are measured.

behavior is considered to be a peculiar phenomenon to

The optically induced rotation signal for thematerials that have the electromagnetic effect in whichpump of 1300 nm observed at 7 K shows a damped

spin and lattice are correlated. The relaxation rate ofoscillation in the picosecond region. From its Fourier the fast component diverges around 200 K. This
spectrum, it was found that the oscillation frequency is divergence behavior away from the Néel temperature
about 0.285 THz. When a magnetic field up to 5T wasis thought to be related to an activation energy process.

Electric-field induced magnetization in YIG

effect below 125 K. Furthermore, a second-orderobserved by Faraday rotation

magnetoelectric effect at low temperatures was

Y. Mushiaki1, K. Fujimoto1, T. Hasunuma1, and T.

reported in the recent study.

Kohmoto1,2

In the present study, we observed the electric-

1

Graduate School of Science, Kobe University

field

2

Molecular Photoscience Research Center, Kobe

magnetoelectric effect in YIG (0.3 mm). The

University

magnetization is detected as the Faraday rotation of a(iCAMP 2020)

transmitted probe beam (1064 nm), using a

Yttrium iron garnet (YIG, Y3Fe5O12) is a ferrimagnetic

polarimeter. In our experiment, the electric andinducedmagnetization

causedbythematerial with a Curie temperature 560 K and is known magnetic fields were applied parallel to the direction
to show a large Faraday effect. It has been reported thatof the probe beam.

YIG shows a second-order magnetoelectric effect at

The Faraday-rotation amplitude observed at 100

room temperature and a first-order magnetoelectric K has a linear dependence on the electric field in the35magnetic field of +1 T, which means the first-order second order effects for the electric field ( r1 + r2 = 1).
magnetoelectric effect at 100 K. While that observed

From the temperature dependence of the fraction r1

at 225 K shows the first and second orderand r2 , it was found that, at lower temperatures, themagnetoelecric effect. The observed Faraday-rotation

first-order effect is dominant, and that the fraction r2

amplitude S can be considered to be a sum of twoof the second-order effect increases suddenly aroundcomponents linear and quadratic in the electric field.

200 K.

We can define the fractions r1 and r2 of the first and36

Original Papers
authors
Yasuhiro Kobori, Masaaki
Fuki, Shunta Nakamura,
Taku Hasobe
Yulian Han, MorihikoHamada, I-Ya Chang, Kim
Hyeon-Deuk, Yasuhiro
Kobori, Yoichi Kobayashi
Zhujun Zhang, Hiroki
Nagashima, Takashi
Tachikawa

発表論文
title
Geometries and Terahertz Motions
Driving Quintet Multiexcitons andUltimate Triplet-Triplet Dissociations via
the Intramolecular Singlet-Fissions
Fast T-Type Photochromism of Colloidal
Cu-Doped ZnS Nanocrystals

Ultra-Narrow Depletion Layers in
Hematite Mesocrystal-Based
Photoanode for Boosting Multihole
Water Oxidation
Izuru Karimata, Takashi
In Situ Exploration of the Structural
TachikawaTransition during Morphology‐ andEfficiency‐Conserving Halide Exchange
on a Single Perovskite Nanocrystal
Ji Young Hwang, Gun-hee Crystal phase-dependent generation ofMoon, Bupmo Kim, Takashi mobile OH radicals on TiO2: Revisiting
Tachikawa, Tetsuro Majima, the photocatalytic oxidation mechanism
Seungwoo Hong, Kangwoo of anatase and rutile
Cho, Wooyul Kim,
Wonyong Choi
Naoya Haraguchi, Tomoki Formation of Mixed-Valence
Okunaga,Yuto Shimoyama, Luminescent Silver Clusters via CationNaoki Ogiwara, Soichi
Coupled Electron-Transfer in a RedoxActive Ionic Crystal Based on a
Kikkawa, Seiji Yamazoe,
Miki Inada, Takashi
Dawson-type Polyoxometalate with
Tachikawa, Sayaka Uchida Closed Pores
Tatsuya Watase, Minoru
Unraveling Hidden Correlations between
Sohmiya, Zhujun Zhang,
Molecular Diffusivity and Reactivity inYasuhiro Kobori, Takashi
Ruthenium Complex-Modified
Tachikawa
Mesoporous Silica
Kohei Tada and Shunji
Hyperfine-resolved high-resolution laser
Kasahara
spectroscopy interaction constants of
14
NO2 radical in 15885 cm-1 energy
regionKaoru Ohta, Yuichi
Dynamic Behavior of Photogenerated
Hiramatsu, Kohtaro
Charge Carriers in DiketopyrrolopyrroleTakahashi, Mitsuharu
Linked Tetrabenzoporphyrin-Based Bulk
Suzuki, Hiroko Yamada, and Heterojunction Thin Films Probed with
Keisuke Tominaga
Time-Resolved Terahertz Spectroscopy
Masaki Okuda, Takato
Theoretical Modeling for Electronic
Hiramatsu, Mitsuru Yasuda, Structure of Polyiodide Species Included
Mika Ishigaki, Yukihiroin α-Cyclodextrin
Ozaki, Michitoshi Hayashi,
Keisuke; Tominaga, and Eri
Chatani
Norifumi Moritsugu,
Molecular Mechanism of Acceleration
Takafumi Nara, Shin-ichi
and Retardation of Collective Orientation
Koda, Keisuke Tominaga,
Relaxation of Water Molecules inand Shinji Saito
Aqueous Solutions
Huiqiang Lu, Sergei G.
Macromol Simultaneous Visualization ofKazarian, Harumi Sato
Phase Separation and Crystallization in
PHB/PLLA Blends with In Situ ATRFTIR Spectroscopic Imaging

37

journalVol.
J. Phys. Chem. B 124

page
9411–9419

J. Am. Chem.
Soc.

doi.org/10.10
21/jacs.0c102
36

year
2020.9.26

Angewt. Chem.
Int. Ed.

59

9047-9054

2020.3.15

Angewt. Chem.
Int. Ed.

59

2548-2553

2020.10.1
9Appl. Catal. B

286

1199052021.1.16

in press2021.3.18

Eur. J. Inorg.
Chem.

J. Phys. Chem.
C

124

21502-21511

2020.9.8

J. Mol. Struct.

1218

128529/1-92020.5.27

J. Photochem.
Photobiol.. A:
Chemistry

400

1126932020

J. Phys. Chem.
B.

124

4089-4096

2020.5.27

J. Phys. Chem.
B.

124

11730-11737

2020.12.1
5

Macromolecules

53

9074

2020.10.7

Tatsuro Nasu, Yukihiro
Ozaki, Harumi Sato

Study of changes in water structure andinteractions among water, CH2, and
COO− groups during water absorption inacrylic acid-based super absorbent
polymers using Raman spectroscopy
Yumiko Yamamoto,Differences in Intermolecular
Hiromichi Hoshina,
Interactions and Flexibility between
Harumi Sato
Poly(ethylene terephthalate) andPoly(butylene terephthalate) Studied by
Far-Infrared/Terahertz and LowFrequency Raman Spectroscopy
Takashi Kunimoto, Yoshiko Development of Eu2+ and Mn2+ coFujita, Hiroshi Kajiyama,
activated silicate phosphor for plant
Tetsuo Honma, Hideki
cultivation light source
Kawaguchi, Tadashi
Ishigaki, Koutoku Ohmi,
Kentaro Ohshima, Daisuke
Miyazaki, Yu Saito, Shigeo
Hara, Takahiro Sakurai,
Susumu Okubo, and Hitoshi
Ohta
Eiichi MATSUOKA, Yasuo Magnetic and Transport Properties of
IWAKIRI, Akihiro
New Cubic compounds Ce6Pd13Cd4 andOSHIMA, Hitoshi
R6Pd13Zn4 (R = Pr, Nd) with the
SUGAWARA, Takahiro
Octahedral Rare-Earth Sublattices
SAKURAI, and Hitoshi
OHTA
Ryota SHIBUYA, Eiichi
Magnetic, Transport, and Thermal
MATSUOKA, Hitoshi
Properties of New Cubic Compounds
SUGAWARA, Takahiro
Ce6Mg23Z (Z = C, Si, Ge)
SAKURAI, and Hitoshi
OHTA
Proximity coupling of superconducting
Takashi Uchino , Nanami
nanograins with fractal distributions
Teramachi, Ryosuke
Matsuzaki, Emi Tsushima,
Shusuke Fujii, Yusuke Seto,
Kazuyuki Takahashi, Takao
Mori, Yutaka Adachi,
Yukihito Nagashima,
Yoshifumi Sakaguchi,
Kazuki Ohishi, Akihiro
Koda, Takahiro Sakurai andHitoshi Ohta
E. Ohmichi, T. Okamoto, T. Zero-Field Splitting Parameters of Hemin
Sakurai, H. Takahashi, S.
Investigated by High-Frequency andOkubo, H. Ohta
High-Pressure Electron Paramagnetic
Resonance Spectroscopy
A. Miyawaki, T. Mochida, The Impact of the Next-Nearest
T. Sakurai, H. Ohta, and K. Neighbor Dispersion Interactions on Spin
Takahashi
Crossover Transition Enthalpy Evidenced
by Experimental and Computational
Analyses of Neutral π-Extended
Heteroleptic Fe(III) Complexes
J. Setsune, S. Omae, Y.
Synthesis, Structure, and Magnetic
Tsujimura, T. Mochida, T.
Properties of Linear Trinuclear CuII and
Sakurai and H. Ohta
NiII Complexes of Porphyrin Analogues
Embedded with Binaphthol Units

38

Spectrochimica
Acta Part A

250

1193052020.12.1
1

Macromolecules

54

1052

2021.1.7

Jpn. J. Appl.
Phys.

58

JPS Conf. Proc.

30

011110/1-6

2019.9JPS Conf. Proc.

30

011109/1-5

2019.9Phys. Rev. B

101

035146/1-12

2020.1

Appl. Mag. Res.
(Invited review)

51

1103-1115

2020.8Inorganic
Chemistry

59

12295-12303

2020.8Symmetry121610/1-22

2020.92019.5

E. Ohmichi, T. Okamoto, H. Mechanically Detected Terahertz
Takahashi, H. Ohta
Electron Spin ResonanceAppl. Mag. Res.
(Invited review)in press

Yoshiki Kuwata, Hisashi
Nonmagnetic first-order phase transition Phys. Rev. B
Kotegawa, Hideki Tou,in the nonsymmorphic NbCrP
Hisatomo Harima, QingPing Ding, Keiki Takeda,
Junichi Hayashi, Eiichi
Matsuoka, Hitoshi
Sugawara, Takahiro Sakurai,
Hitoshi Ohta, and Yuji
Furukawa
T. Sakurai, B. Rubrecht,
Pressure control of the magnetic Phys. Rev. B
L. T. Corredor, R. Takehara, anisotropy of the quasi-two-dimensional
M. Yasutani, J. Zeisner,van der Waals ferromagnet Cr2Ge2Te6
A. Alfonsov, S. Selter,
S. Aswartham, A. U. B.
Wolter, B. Büchner, H.
Ohta, and V. Kataev
H. Takahashi, Y. Ishikawa, Force detection of high-frequency electron Appl. Phys. Lett.
T. Okamoto, D. Hachiya,
spin resonance near room temperature
K. Dono, K. Hayashi,using high-power millimeter-wave source
T. Asano, S. Mitsudo,
gyrotron
E. Ohmichi, and H. Ohta
Ryo Ogawa, Tatsunori
Microwave Hall effect measurement for
J. Appl. Phys.
Okada, Hideyuki Takahashi, materials in the skin depth region
Fuyuki Nabeshima andAtsutaka Maeda

in press

39

103024404/1-8

2021.1

118

022407/1-5

2021.1129015102/1-14

2021.1

Invited Talks (domestic and international)
発表者氏
名

開催時期

開催地

小堀康博
Y. Kobori

2020.
9.10

onlineinvite

2020.
12.12

onlineinvite

2020.
12.3

オンライン

invite

2020.
3.1

オンライン

2020.
3.20

招待講演(国内および国際研究集会)

学会名

講演題目

Annual Meeting on
Photochemistry 2020 at
Online6th Kanto Area Spin
Chemistry Meeting(KASC 6)
第 30 回キャラクタリゼーション講習会

JPA Award 2019 Award Lecture: Photon-to-Energy
Conversion Mechanisms Revealed by Quantum
Effects on Electron Spin Polarization
Conformation Changes in IntramolecularMultiexciton Spins

invite光機能材料研究会 第81 回講演会

単一分子・単一粒子蛍光顕微鏡を用いた光触媒反応のその場観測

オンライン

invite

日本化学会 第 101 春
季年会 (2021)

Single-Particle Emission Imaging of StimulusInduced Structural Changes

2020.
12.9

Singapore(online)inviteAsian Spectroscopy
Conference

THz Molecular Science in Condensed Phases

2021.3.
8-9

University of
Fukui(online)inviteTHz Molecular Science in Condensed Phases

2020.
10.10

Beijing(online)invite8th International
Workshop on FarInfrared Technologies(IW-FIRT 2021)
SPIE Asian Photonics

2020.
12.20

Kolkata,India(online)University of
Fukui(online)inviteICCAES 2020

invite8th International
Workshop on FarInfrared Technologies(IW-FIRT 2021)

plenaryorinvite立川貴士
T.
Tachikawa

富永圭介
K.
Tominaga

張峰
F. Zhang佐藤春実
H. Sato
(人間発達
環境学研
究科)
太田仁
H. Ohta

2021.3.
8-9

2020.9.
28-10.2

Kazan,
invite Modern Development
Russia (Onof Magnetic Resonancesite+Online)
2020

2020.11. Buffalo,
plenary IRMMW-THz 2020
8-13
USA
(Online)高橋英幸
2021. 3. University of invite 8th International
Workshop on FarH. Takahashi 8-9
Fukui
Infrared Technologies(online)(IW-FIRT 2021)
赤木暢
2021. 3. University of invite 8th International
M. Akaki
8-9
Fukui
Workshop on Far(online)
Infrared Technologies(IW-FIRT 2021)
櫻井敬博
2021.3. The Institute invite International
T. Sakurai
22-26
for Solid
Workshop on Quantum(研究基盤
State Physics
Magnets in Extreme
センター）(online)Conditions

40

単一分子・単一粒子蛍光顕微鏡を用いた光触媒反応のその場観測Interpretation of THz Intensities of Molecular
Crystals: the Role of Mixing between
Intermolecular and Intramolecular Vibrations
Towards Establishing THz Vibrational
Spectroscopy in Molecular Crystalline Systems
Intermolecular hydrogen bonding of polymer byterahertz and low-frequency Raman spectroscopy

Multi-extreme THz ESR: present and future

Recent Developments of Multi-Extreme THz ESR

Force-detected high frequency electron spinresonance at 154 GHz using high-power
millimeter-wave source gyrotron
Pulsed high-field ESR in multiferroic åkermanite
materials

Development of Multi-extreme THx ESR
Systems and Its Application to Orthogonal Dimer
Spin Substance SrCu2(BO3)2

Presentation at conferences (international and domestic)oral orposter
oral

発表者氏名

開催時期

開催地

小堀康博
Y. Kobori

2020.
11.15

オンライン

張峰
F. Zhang

2020
11.10

Buffalo,USA(online)oral

IRMMW-THz 2020

2020.
11.12

Buffalo,USA(online)Oral

IRMMW-THz 2020

2020.12. Singapore
8-10(online)posterAsia Spectroscopy Conference

太田仁
H. Ohta

2020.
11.27

オンライン

Oral

第 4 回スピン系物理研究会

大久保晋
S. Okubo

2020.9.
8-11

オンライン

Oral

日本物理学会 2020 年 秋季大会

2020.10. オンライン
29-30

Oral

第 29 回（2020 年度）日本赤外 三角格子反強磁性体 CsFeCl3 の圧力下線学会研究発表会
テラヘルツ ESR による研究

2020.11. オンライン
13-15

Oral

第 59 回電子スピンサイエンス学会年会

圧力下 ESR 測定によるスピンギャップ系
CsFeCl3 の圧力下誘起磁気相の研究

2021.
1.29

オンライン

Oral

第 18 回赤外放射応用関連学
会等年会

テラヘルツ電子スピン共鳴の低次元磁性体への応用

2021.3.
12-15

オンライン

Oral

第 76 回日本物理学会年次大会

ダイマー系化合物 CoSeO3･2H2O の高周波 ESR 測定 IV

20209.7 オンライン

Oral

第七回西日本強磁場科学研究 熱的な検出方法による高周波 ESR の高会
感度化2020.9.
8-11

オンライン

Oral

日本物理学会 2020 年 秋季大会

2020.10 オンライン
29-30

Oral

第 29 回（2020 年度）日本赤外 154GHz ジャイロトロンを用いた力検出型線学会研究発表会
高周波 ESR 測定

2020.11 オンライン
13-15

Oral

第 59 回電子スピンサイエンス
学会年会

力検出法の角度回転高周波 ESR への
応用

2021.
3.10

オンライン

Oral

2020 年度福井大学遠赤外領域開発研究センター共同研究
成果報告会

高強度テラヘルツ光源を使用した力検出型電子スピン共鳴分光

2021.3.
12-15

オンライン

Oral

第 76 回日本物理学会年次大会

熱検出型高周波電子スピン共鳴法の開発2020.9.
8-11

オンライン

Oral

日本物理学会 2020 年 秋季大会

CuFeO2 における圧力下電子スピン共鳴

2020.11 オンライン
.3-15

Oral

第 59 回電子スピンサイエンス
学会年会

マルチフェロイック Sr2CoSi2O7 における
ESR 方向二色性

2020.7posterInternational Conference on
Condensed Matter PhotoPhysics 2020

Spatial and temporal dynamics of thermal
diffusion in clathrate compounds

高橋英幸

赤木暢

河本敏郎
(理学研究
科）

奈良
(on line)

学会名

一般講演
講演題目

第 59 回電子スピンサイエン 分子内一重項分裂によるスピン相関
ス学会年会
三重項対生成に対する振電効果

41Interpretation of THz Intensities of
Molecular Crystals: the Role of Mixing
between Intermolecular andIntramolecular Vibrations
Determination of the Fine Structure of a
Halide Perovskite using High-resolution
THz Spectroscopy and Solid-state
Density Functional Theory
Determination of the Fine Structure of a
Halide Perovskite using THz
Spectroscopy
三角格子反強磁性体 CsFeCl3 における
圧力誘起磁気相転移の観測
CsFeCl3 の圧力誘起磁気相の ESR による研究 III

154GHz ジャイロトロンを用いた室温における力検出型 ESR

櫻井敬博
(研究基盤
センタ
ー）

原茂生
(研究基盤
センタ
ー）
齋藤佑
(研究基盤
センタ
ー）

2020.9.
8-11

熊本(on line)poster

2020.9.
8-11

オンライン

Oral

2020.10. オンライン
29-30

Oral

第 29 回（2020 年度）日本赤外 圧力下サブミリ波 ESR 装置の開発と応用
線学会研究発表会

2020.11. オンライン
13-15

Oral

第 59 回電子スピンサイエンス 高圧力下強磁場 ESR システムの開発と学会年会
常磁性化合物 Co Tutton 塩への応用

2020.12. オンライン
1-3

Oral

2021.3.
12-15

オンライン

PosterAsia-Pacific Conference on
Research in High Magnetic
Fields & KINKEN Materials
Science School 2020 for Young
Scientists
第 76 回日本物理学会年次大会

2021.3.
12-15

オンライン

Poster

第 76 回日本物理学会年次大 ACo2(SeO3)3 ・ 3(H2O)(A=Sr, Ba) 単 結 晶
会育成の試みと光水熱合成炉の開発

Oral

第 59 回電子スピンサイエンス 極安定パーフルオロアルキルラジカルの学会年会
低温 ESR 測定

2020.11 オンライン
13-15

日本物理学会 2020 年秋季大会

クラスレート化合物における熱拡散の空間的時間的ダイナミクス：格子拡散とキャ
リア拡散
日本物理学会 2020 年秋季大 三角格子反強磁性体 CsCuCl3 の高圧下会
強磁場 ESRII

42

Development of high-pressure THz ESR
system and its application to triangularlattice antiferromagnet CsCuCl3

圧力下 THz ESR 装置における圧力較正手法の開発と応用

Presentation by Graduate Students and Postdocs

院生、ポストドクの学会発表

指導教員

発表者氏名

学年

時期

立川貴士

田上嘉尉

M1

2020.3.21 日本化学会 第 101 春季
年会 (2021)

巨視的な自発分極を有する BiOIO3 における光触媒反応の単一粒子蛍光観測

清水暘

M1

2021.3.
9-10

5th Asian Workshop on
Molecular Spectroscopy

Ultrahigh-resolution spectroscopy of transstilbene: nonplanar structure in the ground state

中島康輔

M1

2021.3.
9-10

5th Asian Workshop on
Molecular Spectroscopy

Ultrahigh-resolution Spectroscopy ofacetaldehyde: Torsion-inversion-rotationinteraction in the excited state

Lou Serafin D2
Lozada2020.10.
19-23

38th SPP Physics
Conference (online)

Broadband dielectric relaxation of hydrated
bentonite

Lou Serafin D2
Lozada2020.12.
8-10

7th Asian Spectroscopy
Conference 2020 (online)

Broadband dielectric spectroscopy from subGHz to THz frequency region on hydrated
bentonite

藤井 悠生

M2

2020.12.
8-10

7th Asian Spectroscopy
Conference 2020 (online)

Hydrogen Bond Dynamics of 9-Fluorenone
Derivatives in Water Studied by TwoDimensional Infrared Spectroscopy

高本 和也

M1

2020.12.
8-10

7th Asian Spectroscopy
Conference 2020 (online)

Charge Transfer Dynamics of 9-Arylcarbazole
Studied by Femtosecond Transient Absorption
Spectroscopy

西前 篤志

M2

2020.9.16 高分子討論会

那須 達郎

M2

2020.9.16 高分子討論会

能智 真央

M2

2020.9.16 高分子討論会

振動分光法を用いたεポリ（L）リジンの吸水による高次構造の研究

西前 篤志

M2

2020.7.10 第 66 回高分子研究発表会（神戸）

ポリ（グリコリド-ラクチド）共重合体の低波数領域における振動モードの組成比依存性

能智 真央

M2

2020.7.10 第 66 回高分子研究発表
会（神戸）

低波数領域の振動分光法を用いたεポリ(L)リ
ジンの高次構造の研究

那須 達郎

M2

2020.7.10 第 66 回高分子研究発表
会（神戸）

高吸水性樹脂中の水の振動モードの低波数領域と高波数領域の比較

吉江大成

M1

2020.7.10 第 66 回高分子研究発表
会（神戸）

生分解性ポリマーブレンドのテラヘルツイメージ
ングによるモルフォロジー観察

那須達郎

M2

2020.5.27 第 69 回高分子学会年次大会

低波数ラマン分光法と赤外分光法によるアクリ
ル酸系高吸水性樹脂中の水の構造

吉江大成

M1

2020.5.27 第 69 回高分子学会年次大会

THz イメージングによるポリヒドロキシブタン酸／ポリ乳酸ブレンドの相分離

八谷大輝

M2

2020.9.
8-11

日本物理学会 2020 年
秋季大会

非反転対称磁性体 CuB2O4 のテラヘルツ領域
における力検出型 ESR 分光

恒石一義

M2

2020.9.
8-11

日本物理学会 2020 年
秋季大会

S=1/2 反強磁性鎖 KCuMoO4(OH)の単結晶
ESR 測定 III

船越風太

M2

2020.9.
8-11

日本物理学会 2020 年
秋季大会

ダイマー系化合物 CoSeO3･2H2O の高周波
ESR 測定 III

安谷佳将

M2

2020.9.
8-11

日本物理学会 2020 年
秋季大会

圧力下強磁場 ESR 装置における圧力較正手法の開発 IIIT.Tachikawa

笠原俊二
S. Kasahara

富永圭介
K.Tominaga

佐藤春実
H. Sato太田仁
H. Ohta

学会名

講演題目

テラヘルツおよび低波数ラマン分光法による
PGAPLA 共重合体の組成比変化に伴う高次構造の研究
ラマン及び赤外スペクトルに現れる水と高吸水性樹脂中の水の振動モードの比較

43

船越風太

M2

2020.10.
29-30

第 29 回（2020 年度）日本
赤外線学会研究発表会

ダイマー系化合物 CoSeO3･2H2O のテラヘルツ
波 ESR 測定藤岡廉

M2

2020.10.
29-30

第 29 回（2020 年度）日本
赤外線学会研究発表会

力検出型電子スピン共鳴測定の感度向上に向けたテラヘルツ帯 bull's eye アンテナの作製

八谷大輝

M2

2020.10.
29-30

第 29 回（2020 年度）日本
赤外線学会研究発表会

非反転対称磁性体 CuB2O4 の THz 領域における角度回転力検出型 ESR 測定

恒石一義

M2

2020.10.
29-30

第 29 回（2020 年度）日本
赤外線学会研究発表会

S=1/2 反強磁性鎖 KCuMoO4(OH)の微小単結晶試料を用いたテラヘルツ力検出 ESR 測定

安谷佳将

M2

2020.10.
29-30

第 29 回（2020 年度）日本
赤外線学会研究発表会

多重極限 ESR 装置における圧力較正手法の
確率と応用

安谷佳将

M2

2020.11.
13-15

第 59 回電子スピンサイエ
ンス学会年会

多重極限 ESR 装置における圧力較正装置の
開発と応用

船越風太

M2

2020.11.
13-15

第 59 回電子スピンサイエ
ンス学会年会

スピンダイマー系化合物 CoSoO3・2H2O の高周
波 ESR 測定恒石一義

M2

2020.11.
13-15

第 59 回電子スピンサイエ
ンス学会年会

S=1/2 反強磁性鎖 KCuMoO4(OH)の微小単結晶試料を用いたメンブレン力検出 ESR 測定

藤岡廉

M2

2020.11.
13-15

第 59 回電子スピンサイエ
ンス学会年会

力検出型 ESR 測定の高感度化に向けたテラヘ
ルツ帯 bull's eye アンテナの作製と評価

八谷大輝

M2

2020.11.
13-15

第 59 回電子スピンサイエ
ンス学会年会

非反転対称磁性体メタホウ酸銅のテラヘルツ領域における角度回転力検出型 ESR 分光

竹原良祐

M1

2020.11.
13-15

第 76 回日本物理学会年次大会

スピンギャップ系物質の高圧下 THz ESR 測定

小路悠斗

M1

2020.11.
13-15

第 76 回日本物理学会年次大会

連続波長可変テラヘルツ光源を用いた周波数
掃印型電子スピン共鳴分光法の開発

M1

2020.7

International Conference
on Condensed Matter
Photo-Physics 2020

Electric-field induced magnetization in YIG
observed by Faraday rotation

岩崎祐典

M2

2020.7

International Conference
on Condensed Matter
Photo-Physics 2020

Terahertz
time-domain
spectroscopy
antiferromagnetic cobalt oxide

前田悠貴

M2

2020.7

International Conference
on Condensed Matter
Photo-Physics 2020

Lattice dynamics in an antiferromagnet chromium
oxide

前田悠貴

M2

2020.9.
8-11

日本物理学会 2020 年
秋季大会

反強磁性体酸化クロムにおける高速格子ダイナ
ミクス

岩崎祐典

M2

2020.9.
8-11

日本物理学会 2020 年
秋季大会

反強磁性体酸化コバルトにおけるテラヘルツ時
間領域分光

虫明侑一郎

M1

2020.9.
8-11

日本物理学会 2020 年
秋季大会

YIG における電場誘起磁化

岩崎祐典

M2

2020.10.
26-28

日本分光学会年次講演会

遷移金属酸化物反強磁性体におけるテラヘル
ツ時間領域分光前田悠貴

M22020.10.
26-28

日本分光学会年次講演会

反強磁性体 Cr2O3 における高速格子ダイナミク
ス

虫明侑一郎

M1

2020.10.
26-28

日本分光学会年次講演会

YIG における電場誘起磁化

岩崎祐典

M2

2020.12.
11-12

第 31 回光物性研究会

反強磁性体酸化コバルトにおけるテラヘルツ時
間領域分光

河本敏郎
虫明侑一郎
T. Kohmoto

44

in

前田悠貴

M2

2020.12.
11-12

第 31 回光物性研究会

反強磁性体酸化クロムにおける高速格子ダイナ
ミクス

虫明侑一郎

M1

2020.12.
11-12

第 31 回光物性研究会

YIG における電場誘起磁化と光励起キャリアの拡散ダイナミクス

45

Books著者（共著者も含む）

著書
書名

出版社名

46

ページ数

発行年

Other Publications

参考論文・記事・報告

著者

タイトル

出版物名

巻・号・ページ
38 巻・4 号

立川貴士

太陽光水素製造へ向けたヘマ FC レポート
タイトメソ結晶光電極の開発

2020

立川貴士

ヘマタイトメソ結晶光電極を 月刊機能材料
用いた太陽光水素製造

40 巻・8 号

2020

立川貴士

赤錆を用いて水と太陽光から クリーンエネルギー 29 巻・3 号・
水素を製造
37-42

2020

Carlos R. Baiz, Bartosz
Błasiak, Jens Bredenbeck,
Minhaeng Cho, Jun-Ho Choi,
Steven A. Corcelli, Arend G.
Dijkstra, Chi-Jui Feng, Sean
Garrett-Roe, Nien-Hui Ge,
Magnus W. D. HansonHeine, Jonathan D. Hirst,
Thomas L. C. Jansen,
Kijeong Kwac, Kevin J.
Kubarych, Casey H.
Londergan, Hiroaki
Maekawa, Mike Reppert,
Shinji Saito, Santanu Roy,
James L. Skinner, Gerhard
Stock, John E. Straub, Megan
C. Thielges, Keisuke
Tominaga, Andrei
Tokmakoff, Hajime Torii, Lu
Wang, Lauren J. Webb, andMartin T. Zanni
岩崎祐典，喜多将之，爰川
優太，守安毅，河本敏郎

Vibrational Spectroscopic Map, Chem. Rev.
Vibrational Spectroscopy, andIntermolecular Interaction

2020

120 (15) 71527218

反強磁性体酸化コバルトにお 光 物 性 研 究 会 論 文 31 巻・45-48
けるテラヘルツ時間領域分光
集

発行年

2020

前田悠貴、川畑将馬、三井 反強磁性体酸化クロムにおける 光 物 性 研 究 会 論 文 31 巻・141-144
宏務、谷口弘樹、疋田崚、 高速格子ダイナミクス
集
河本敏郎

2020

虫明侑一郎、永富寛弥、藤 YIG における電場誘起磁化と光 光 物 性 研 究 会 論 文 31 巻・257-260
本恵輔、河本敏郎
励起キャリアの拡散ダイナミクス 集

2020

47

Lecture to Public

講演、模擬授業など

氏名
小堀康博

講演題目
集会名
日時
場所
電子スピンの量子･動的 “光”機到来！Q コロ 2020.12.2 https://www.youtube.com/watch?v=2ThnnebIjnk
効果で読み解く光エネ キウム
ルギー変換のしくみ

笠原俊二

温室効果ガスってな 第 15 回女子中高生 2021.3.20 神戸大学(オンライン)
ーに？
のための関西科学塾

48

Awards受賞

氏名

受賞研究題目

賞名藤井悠生

Hydrogen Bond Dynamics of 9-Fluorenone
Derivatives in Water Studied by TwoDimensional Infrared Spectroscopy

八谷大輝

非反転対称磁性体 CuB2O4 の THz 領域における角度回転力検出型 ESR 測定

IAS-Laser 21 Poster
Asian Spectroscopy Conference 2020
Award at Asian
Spectroscopy
Conference 2020
第 29 回（令和 2 年 日本赤外線学会度）優秀発表賞

安谷佳将

多重極限 ESR 装置における圧力較正手法の 第 29 回（令和 2 年 日本赤外線学会
確立と応用度）優秀発表賞

安谷佳将

圧力較正装置を備えた新しい多重極限 ESR装置の開発と応用

優秀発表賞

49

団体、学会名修士論文審査会（2021 年 3 月）

Conference Organization
氏名

学術集会

立川貴士

笠原俊二、馬場
正昭、富永圭介

笠原俊二

学術集会の開催
共同主催者

場所

時期

先端融合研究環 開拓
プロジェクト「階層縦断的アプローチによる革新的光エネルギー変換系の開拓」ワークシ
ョップ 〜マテリアル
サイエンスの最前線〜

瀧川記念学術交流会館大会議室+online

2020.11.10

参加者
概数
59 名

テラヘルツ分子科学研究会「高分解能分光の最近の進展と今後の展
望〜テラヘルツ波とのinterplay」
第 21 回分子分光研究会

神戸大学百年
記念館+online

2020.12.3

約 20 名石川春樹、水瀬賢太

Online2021.3.8

約 60 名Thomas Schultz, YenChu Hsu, Shuiming Hu

瀧川記念学術交流会館大会議室+online

2021.3.9-10

約 100 名笠原俊二、馬場正昭

5th Asian Workshop on
Molecular Spectroscopy

太田仁、大久保晋

分子フォト研究会「第４回スピン系物理研究会 スピン系研究の開拓前線」

online2020.11.27

約 50 名太田仁、大久保 第 15 回量子スピン系研
晋究会

online2021.1.5

36 名

50

Seminars

セミナー

Date
2020.12.14

Name
松本 正茂

Affiliation
静岡大学理学部

Title
三角格子反強磁性体 CsFeCl3 における
磁気励起

2021.3.11

今堀 博

京都大学大学院工学研究科
分子工学専攻光電荷分離工学：モデル系から光エネルギー変換、細胞操作まで

51

Molecular Photoscience Research Center
Kobe University,
Nada, Kobe 657-8501 Japan
Tel: +81-78-803-5761
URL: http://www.research.kobe-u.ac.jp/mprc/about/index_e.html (English)〒657-8501
神戸市灘区六甲台町 1－1
神戸大学分子フォトサイエンス研究センター
電話番号 078-803-5761
http://www.research.kobe-u.ac.jp/mprc/index.html （日本語）