01

Front image:

Advisory Board

Semiconductor Micro /Nanomechanical Devices

The aim of the Advisory Board is to provide an objective
evaluation of our research plans and activities to enable

Miniaturizing mechanical resonators,
such like doubly clamped beams andus to employ strategic management in a timely manner. At

cantilevers, into micro and nanometer

this meeting, BRL researchers had a lunch and a poster

scales makes them extremely sensitive

session with the board members, where they had chances toto an externally applied small force.
Such a structure, in addition, canpresent their researches to the board members in a casual

generate large strain by its elastic

atmosphere. Next 10th meeting will be held in 2019.

deformation, providing a novel
tool to manipulate local material
properties. We study the integrated
devices of mechanical resonatorswith semiconductor heterostructures,
aiming to develop novel functions ofsemiconductor fine structure devices.

N T T- B R L S e m i n a r
We invite distinguished researchers in the world to hold an
in-house seminar. This year, we had 30 seminars dedicatedto our research field and shared latest research results withthe guests.

MessagefromDirector

We at NTT Basic Research Laboratories (BRL) are extremely
grateful for your interest and support with respect to our research
activities.
BRL’s missions are to promote progress in science andinnovations in leading-edge technology to advance NTT's
business. To achieve these missions, researchers in fields
including physics, chemistry, biology, mathematics, electronics,
informatics, and medicine, conduct basic research on materials
science, physical science and optical science.
Our management principle is based on an "open door" policy.
For example, we are collaborating with many universities andresearch institutes all over the world as well as other NTT
laboratories. We also organize "Science Plaza" as an open
house, "ISNTT", and other international conferences at Atsugi

02

N T T- B R L S c h o o l
NTT-BRL School is held to foster young researchers and topromote the international visibility of NTT. In 2017, on thesubject“The principles of solid state quantum computation”,
we had lectures by Prof. Kae Nemoto (NII), Prof. Yasunobu
Nakamura (The University of Tokyo), and Hiroki Takesue(NTT-BRL). There were also laboratory tours and a poster
session.

ISNTTInternational School and Symposium on Nanoscale Transport and phoTonics

International symposium and school“ISNTT”, bienniallyheld in NTT-BRL, brought together leading scientists,
researchers, and graduate students to share their latest
research and discoveries related to the physics andtechnology of nanoscale structures. We encouraged frankand open technical discussions on recent breakthroughs andadvances in related research. In 2017, we had 142 oral/
poster presentations, including a keynote talk by Prof. Serge
Haroche (Laboratoire Kastler Brossel, College de France)and 18 invited talks.

R&D Center to disseminate our research output and to hear
opinions from many people. In addition, we sponsor the "NTTBRL School", which is dedicated to young researchers aroundthe world. To this school, we invite distinguished researchers
from around the world as lecturers to give young researchers
including those at NTT the opportunity to learn from the foremost
authorities and to share ideas with them.
These activities enable us to realize our "open door" policy
and our missions with respect to the promotion of advances inscience and the innovation of leading-edge technology for NTT's
business. Your continued support will be greatly appreciated.
Director of NTT Basic Research Laboratories

03

Organization

NTT Basic Research Laboratories

Director

Tetsuomi Sogawa

Research Planning Section

Materials Science Laboratory

Physical Science Laboratory

Optical Science Laboratory

Executive Manager

Executive Manager

Executive Manager

Executive Manager

Hideki Gotoh

Hideki Yamamoto

P5●Thin-Film Materials

Research Group●Low- Dimensional

Nanomaterials Research
Group●Molecular and Bio Science

Research Group

Akira Fujiwara

P7●Nanodevices ResearchGroup●Nanomechanics ResearchGroup●Superconducting Quantum

Circuit Research Group●Quantum Solid State

Physics Research GroupThe population data of NTT-BRL members●Researcher…98●Research Associate/Specialist…12●Joint Researcher…10●Total International Interns…15●Total Domestic Interns…33

Hideki Gotoh

P9●Quantum Optical State

Control Research Group●Theoretical Quantum

Physics Research Group●Quantum Optical Physics

Research Group●Photonic Nano-Structure

Research Group04
As of Dec. 31, 2018

9th Advisory Board Meeting (January 30, 2017)

Advisory Board
University of California, Berkeley, U.S.A.

Prof. John Clarke

Harvard University, U.S.A.

Prof. Evelyn Hu
Nanophotonics Center

Research Center for Theoretical Quantum Physics

Project Manager

Project Manager

Masaya Notomi

William John Munro

University of Gothenburg, Sweden

Prof. Mats Jonson

Imperial College London, U.K.

Prof. Sir Peter Knight

University of Illinois at Urbana-Champaign, U.S.A.

Prof. Anthony J. Leggett

The University of Texas at Austin, U.S.A.

Prof. Allan H. MacDonald

Forschungszentrum Jülich, Germany

Prof. Andreas Offenhäusser
The University of Queensland, Australia

Prof. Halina Rubinsztein-Dunlop
Max Planck Institute for Solid State Research, Germany

Prof. Klaus von Klitzing

P11

P11

Research Professors
Kwansei Gakuin University

Prof. Hiroki Hibino
National Cerebral and Cardiovascular Center
Japan Research Promotion Society for Cardiovascular Diseases
Sakakibara Heart InstituteTokyo Metropolitan Hospitals Association

Dr. Hitonobu Tomoike (Medical Director)

05

Materials Science Laborator yGroup Introduction

Materials Science
Laboratory
Overview
The aim of the Materials Science Laboratory is to contributeto progress in materials science a n d to revolutio nize
information communication technology by creating novel
materials a n d fu nctio ns through materials d esign a n darrangement control at the atomic and molecular levels .
T h e re s e a rc h g ro u p s t h at c o n stit u te t his la b o rato r y a reinvestigating a wide range of materials including t ypicalcompound semiconductors such as Ga As and GaN ,two - dimensional materials such as graphene, oxide
su percond uctors a nd magnetic materials , cond uctive
polymers, and biological soft materials. We are conducting
innovative materials research based on advanced thin-film
growth technologies and high-precision and high-resolution
m e a s u r e m e n t s of s t r u c t u r e s a n d p ro p e r ti e s a l o n g wit htheoretical studies as well as Materials Informatics.

Multi-source molecular beam epitaxy apparatus:
an enabling technology for high-quality thin films
of complex oxides/nitrides, which is also exploited
as a synthesis method sui generis for novel
superconductors and magnetic materials.

Thin-Film Materials Research Group
Novel Compound Semiconductor Devices

Creation of light- emitting devices over a wide range fromF U V to N I R , high - ef ficiency energ y creation /conversion
devices, and novel multifunctional (optical, electric, andspintronic) devices

Low-Dimensional Nanomaterials ResearchGroup
2D Layered Materials

Creation of ultimately thin functional layered materials foratomic layer electronics

Complex Oxide Thin Films

C re a tio n of t ra il b la zi n g s u p e rc o n d u cto r s a n d m a g n etic
materials beyond conventional concepts

Molecular and Bio Science Research Group
Biocompatible Soft Materials

Development of soft material composites for measurementof deep biological information

Interface Interaction
Creation of biodevices and soft robots
by co ntrolling interactio ns at cell/cell a n d cell/n o n - cell
substance interfaces

Biosensing

O n - chip biosensing devices for biomolecular analysis at
molecular scale

06

Achievements in 2018

(a)	
(c)	
Synthesis

Machinelearning

Intensity y (a.u.)English	
1

Method: Fe L2,3-edges XAS
Material: CoFe2O4
Raw data points: 250

0.5

0Material
database

Analysis710 715 720 725
Photon Energy (eV)730

Reducing data points
Intensity y (a.u.)(b)	

Measurement1

evaluation: σ·sqrt(|μ|)
40 data points
predict
pred ± σ

0.5

0
705

710 715 720 725
Photon Energy (eV)730(a) Cross-sectional TEM image, (b) schematic illustration of valence band edgeand (c) hole concentration of Mg-doped AlN/Al0.75 Ga0.25 N superlattices(Left) Research cycle for the development of novel materials. (Upper right)
Spectrum, which consists of 250 data points, obtained by the conventional
spectroscopy. (Lower right) Spectrum predicted by GPR with 40 data points.

Utilizing a Polarization Field to Increase theConcentration of Holes in AlN/AlGaN Superlattices

High-throughput Spectroscopies Using
Machine Learning

AlG aN - bas ed deep- u ltra v io le t (DUV ) lig h t-e m ittin g d io d e s
and laser diodes are of great interest for applications such as
sterilization and medical treatment due to their small size, lowpower consumption, and long lifetime. The low concentration(<1015 cm -3 ) of holes in p-type AlGaN alloy with high Al content(>70%) is a key issue for device applications. We achieved ahigh hole concentration on the order of 1018 cm -3 in Mg-doped
A l N / A l 0 .75 G a 0 .25 N s u p e r l a t t i c e s b y l o w e r i n g t h e e f f e c t i v e
acceptor ionization energy using large polarization charges
generated at the superlattice interfaces. The findings fromthis study may lead to significant increases in the emission
efficiency of DUV devices.

We developed high-throughput spectroscopies by predicting
spectral shapes with Gaussian process regression (GPR), which
is a basic technique of machine learning. This method allows
us to predict detailed peak structures by sampling only about
one-sixth of the original sample points. The reduction in timeand cost of characterizing specimens afforded by this method
will accelerate development of novel materials. This work is
being carried out in collaboration with NTT Communication
Science Laboratories.

K. Ebata, J. Nishinaka, Y. Taniyasu, and K. Kumakura, Jpn. J. Appl. Phys. 57, 04FH09 (2018).

®	
  医療療⽤用hitoeSo#	  hydrogel	®	
  スポーツ⽤用hitoeS,ﬀ	
  hydrogel	

hitoe®ウェアラブル�
⼼心電図測定システム	
  

10 µm

hitoe電極	  スポーツ・リハビリ分野での�Control	
  of	
  neurite	
  ini,a,on	
  by	
  mechanical	
  property	
  of	
  a	
  hydrogel	
  substrate.	
筋電位計測に活⽤用（試作品）	
  

Y. K. Wakabayashi, T. Otsuka, Y. Taniyasu, H. Yamamoto, and H. Sawada, Appl. Phys. Express 11,
112401 (2018).

“hitoe”	  for	
  medical	
  hitoe	
  wearable	
  electrocardiogram	  measurement	
  system	  hitoe	
  electrode	
  “hitoe”	  for	
  sports	  Spats	
  for	
  myoelectric	  measurement	
  in	
  sports	  and	  rehabilitation（prototype）	
  拡がるhitoe®の実⽤用化展開	
  Expansion of practical use of “hitoe”

東レと共同開発した⽣生体情報の連続計測を可能とする
Cells recognize and respond to external mechanical signals in
機能素材hitoe®を⽤用いた医療療⽤用「hitoe®ウェアラブル
their surrounding microenvironment, such as the extracellular
⼼心電図測定システム」が2018年年9⽉月に東レ・メディカ
matrix (ECM). Here, we investigated how the mechanical
ルより販売開始されました。最⼤大2週間、無充電で連properties of the microenvironment affect neurite initiation by
続⼼心電測定が可能となり、将来の在宅宅医療療における重preparing a hydrogel with various stiffnesses ranging from that
要な計測ツールとなることを期待しています。またof brain tissue. We found that a stiffer substrate suppressed®
hitoe の筋電位計測⽤用ウェアを試作し、各種スポーツ
neuritogenesis. This study provides us with insight not only for
やリハビリなどでの筋活動・筋疲労計測の実証試験を
developing a scaffold for neuronal regeneration, but also for®のグローバル展開を進めながら⾏行行っています。hitoe
designing a compliant
interface between biological tissue and
多様な分野での⽤用途拡⼤大を図っています。	
  implantable devices.

A medical “hitoe wearable electrocardiogram
The wearable electrocardiogram measurement system calledmeasurement system” using functional material “hitoe”,“hitoe”, which is composed of the functional material of thewhich enables continuous measurement of biologicalsame name, enables continuous measurement of biologicalinformation jointly developed with Toray, was launched byinformation. It was jointly developed with Toray Industries, Inc.
Toray Medical in September 2018. This system allows
and has been marketed by Toray Medical since September
continuous
electrocardiogram measurement for maximum
2018 . T h i s s y s t e m a l l o w s c o n t i n u o u s e l e c t r o c a r d i o g r a m
2 weeks with no battery charge, and is expected to be an
measurements to be made for up to two weeks between battery
importanttool for future home medical care. In addition,
charges, and it is expected to be an important tool for future
by
using
a
prototype “hitoe” wear for myoelectric
home medical care. In addition to this development, we aremeasurement,
we are carryingout proof-of–concept
carrying out proof-of-concept
experiments
on a hitoe
prototype
experimentsofmuscleactivity
andmusclefatiguefor myoelectric measurements. This unit measures muscle
measurementin sports
andduring
rehabilitation
etc. We are etc.
activity and muscle
fatigue
sports, rehabilitation,
expandingthe applications
variousfieldsthe
while
Through efforts
like these, weinare
expandingapplications
promptingglobal expansion of “hitoe”.
of hitoe.

Using Scaffold Stiffness to Control Cellular Growth

A. Tanaka, Y. Fujii, N. Kasai, T. Okajima, and H. Nakashima, PLOS ONE 13, e0191928 (2018).

New Uses for“hitoe”

Materials Science Laboratory

705

Theory07

Physical Science Laborator yGroup Introduction

Physical Science
Laboratory
Overview
The Physical Science Laboratory aims to develops e mic o n d u cto r- a n d s u p e rc o n d u cto r- b a s e d d evic e s a n dhybrid-type devices, which will have a revolutionary impact
on the ICT society of the future. We are using high-quality
crystal growth and nanofabrication techniques to explore
novel properties that could lead to nanodevices for ultimate
electronics and novel information processing applications
based on new degrees of freedom such as single electrons,mechanical oscillations, quantum coherent states, electron
correlation, and spins.

Nanodevice Research Group

Single-electron Devices for Ultimate Electronics
Highly accurate, highly sensitive, and low- power devices
based on single charge transfer and detection

Nanodevices with Novel Functions

Novel and high performance nanodevices based on silicon
and hybrid materials

Nanomechanics Research Group

Semiconductor Opto/electromechanics
Novel devices using mechanical functionality insemiconductor fine structures

Phonon Manipulation

P r o p a g a t i o n c o n t r o l o f a c o u s t i c w a ve s u s i n g a r t if i c i a l
structures

Superconducting Quantum Circuit Research
Group
Superconducting Quantum Circuits

Manipulating quantum states using superconducting
devices

Ultimate Quantum Measurement and Sensing

Highly sensitive measurement technologies using quantum
mechanical effects

Q ua ntum Solid State Physics Resea rch
Group

Quantum Transport in Semiconductor Hetero- andNano-structures
Unconventional charge and spin transport phenomena inquantum devices

Coherent Carrier Dynamics in Electronic Devices
Information processing with coherent electron motion3

He/4 He dilution refrigerator used to carryout low-temperature (below 100 milli-kelvins)
experiments for superconducting andsemiconductor quantum devices.

08

Outlet	Blood	
  inlet	Dark	

100 um	Si transistor
Sensing area

Energy	  (eV)	

(Le;)	  A	
  can3lever	  embedding	  bright	
  and	
  dark	  excitons	  (Right)	
  Photoluminescence	
  from	  dark	  excitons	

100 nm	We demonstrated control of the strain-induced coupling
between bright and dark excitons in a cantilever composedof semiconductor heterostructures. Dark excitons areadvantageous for their long lifetime, but they have not beenused in optical devices because photon absorption andemission from them are forbidden. This strain-induced couplingmakes dark excitons optically accessible via bright excitons.
These results will pave the way to new device concepts, suchas optical storage, that take advantage of the long-lived natureof dark excitons.

D2

D1

Added ion （mol/l）

R. Sivakumarasamy, R. Hartkamp, B. Siboulet, J.-F. Dufreche, K. Nishiguchi, A. Fujiwara, and N.
Clement, Nature Mater. 17, 474 (2018).

7+]OLJKW

b axis
Er:YSO crystal

9°
microwave
in

血清導入口

We discovered that a variety of cations in aqueous solution
in contact with the surface of a nanoscale silicon transistor
change the current flowing through the transistor. By
utilizing this phenomenon, we can measure individual cation
concentrations in blood serum. While transistor-based ion
sensors usually require special treatment to distinguishand detect specific ions, our nanoscale transistor does notneed such treatment, which allows for simple and stablemeasurements for biosensors. Additionally, this unique effectin nanoscale silicon transistors may be a means to exploit new
surface chemistry.

R. Ohta, H. Okamoto, T. Tawara, H. Gotoh, and H. Yamaguchi, Phys. Rev. Lett. 120, 267401 (2018).

BJBA

セン

Ion sensing	Selective Layer-free Blood Serum Ionogram
Based on Ion-specific Interactions with aNanotransistor

Mechanical Control of Coupling between
Bright and Dark Excitons


B0

microwaveout

JBA

JBA Flux Shift (A)Magnetic Field (mT)

Ź6'Frequency (GHz)(Top) Schematic diagram. (Bottom) Observed ESR spectra.

ŷŷUHI 

Bright	w/o	
  strain	Transistor sensor	

Surface potential change （AU）	

Couple	w/	
  strain	
 Dark	
  exciton	

Physical Science Laboratory

Can3lever	

Intensity	
  (a.u.)	

10 µm	

Intensity	
  (a.u.)	

Achievements in 2018

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PRQROD\HU 6$0RUDQJH 

Electron Spin Resonance Spectroscopy
Using a Josephson Bifurcation Amplifier

Plasmon Confinement by Modulating theCarrier Density of Graphene

We developed a magnetic field and frequency tunable electron
spin resonance spectroscopy (ESR) scheme using a tunable
Josephson bifurcation amplifier, with good measurement
sensitivity of about 15,000 spins. This scheme is well-suitedfor characterization of more complicated spin systems, suchas Er-doped YSO crystal with anisotropic hyperfine andquadrupole interactions.

Graphene plasmons are attracting much attention forplasmonic device applications owing to their tunability byelectrical means. We investigated plasmon excitations underperiodic carrier density modulation in graphene. Using THz
spectroscopy, we showed that plasmons can be confined by thespatial modulation of the carrier density. This technique can beused to form an electrically controllable plasmonic waveguide.

R. P. Budoyo, K. Kakuyanagi, H. Toida, Y. Matsuzaki, W. J. Munro, H. Yamaguchi, and S. Saito, Phys. Rev.
Mater. 2, 011403 (2018).

N. H. Tu, M. Takamura, Y. Ogawa, S. Suzuki, and N. Kumada, Jpn. J. of Appl. Phys. 57, 110307 (2018).

10

トラ

検

09

Optical Science Laborator yGroup Introduction

Optical Science
Laboratory
Overview
The Optical Science Laboratory is pursuing the developmentof c o re te c h n ologies th at will le a d to in n ovatio ns in
optical communication and optical signal processing andto f u n d a m e nt al s cie ntific p ro g re s s . C e nt ral t h e m e s a requantum communication, physical computing with opticaltechniques, ultra-short light-matter physics pulse light, theoptical frequency standard, and optical and spin properties
in nanostructures.

Q ua ntum Optical State Cont rol Resea rch
Group
Photonic Quantum Communication

Control of quantum state of light and its application to novelcommunication systems

No n -vo n Ne u m a n n Com p u t at io n Usi n g Q u a n t u m
OpticsNew computers based on coupled optical oscillators

Theoretical Q ua ntum Physics Resea rch
Group
Theoretical Quantum Information Science

Proposal and systematic design of quantum computation,communication, network and metrology schemes includingarchitectures.

Quantum Optical Physics Research Group

Ma nip ulation of Ult rafast a n d Ult ra - st a ble L ase r
Field
Explore ultrafast physics and establish the standard opticalfrequency

Nano-scale Physics in Optically-active Materials

Characterize photons, excitons and spins in thesemiconductor nano-structures and rare-earth ions.

Photonic Nano-Structure Research Group
Integrated nanophotonics technologies

Ultra - compact and ultra -low power photonic devices andcircuits, novel photonic phenomena in nanostructures

Instrument to control optical dispersion andchirp for achieving ultrafast laser pulses inattosecond regime.

10

Achievements in 2018
英語版

IAP：Isolated attosecond pulse
NIR：Near-infrared pulse

Chromium doped sapphire(Cr:Al2O3)
1

22

1

0
35

40
45
50
IAP photon energy (eV)44

Optical Science Laboratory

p = 0.85

44

Extreme ultraviolet
spectrometer

12

Energy (eV)p = 0.76

10

8.7 eV(CB)865 eV(IM)

4

IAP
NIR

2
0
-2

z=3

z = 21z = 39z = 57KΓ A
Wave vector

IAP first

z = 75Observation of domain formation process in 2D model
Copyright©2018	  	
  NTT	
  corp.	
  All	
  Rights	
  Reserved.	

1	

Delay (fs) NIR first1 2 3 4 5 6

44
42
40
Period: 667-383 as

0.2

VB

0

H

-2 -1

CB: Conduction band
IM : Intermediate state
VB: Valence band

Cavity circulations z

0

-2 -1
46

38
0.4
ΔOD

Down spin(c)
IAP photon
energy (eV)(b)

p = 0.63

Pump amplitude p(a)Up spinIntensity

p = 1.10

1

22

0

5

1 2 3 4
Delay (fs)

6

-0.1
0.3
0.7
Relative absorbance (ΔOD)(a)Transient absorption attosecond spectroscopy, (b)Energy band structure of
Chromium doped Sapphire, (c)Attosecond electron interferogram

2D Ising Model Simulation with OPO
Network

Ultrafast Electron Oscillation Monitored by
Attosecond Light Source

We simulated a 2D Ising model at low temperature with acoherent Ising machine (CIM) based on a network of the
optical parametric oscillators (OPOs). By observing the domain
formation process in 2D Ising model, we determined that theperformance of the CIM is limited by the freeze-out effect.
We adjusted the pump amplitudes of the OPOs closer to thethreshold to avoid the freeze-out effect and found that the CIM
could reach the ground state of a 2D Ising model consisting of
1,936 spins.

The lightwave field in visible and ultraviolet regions canr e a c h p e t a h e r t z (1015 H z : P H z ) f r e q u e n c i e s . W e o b s e r v e d
the lightwave field-induced electronic dipole oscillations
with 667-383 attosecond (10 -18 sec.: as) periodicity, which
is characterized by an extremely short isolated attosecond
light source. Since electron oscillations are the origin of lightmatter interactions, this study lays the essential groundworkfor exploring various optical phenomena in solids; the ultrafast
time dependence will also be important in studies of electronic
and photonic devices.

Boundary
B-field

1.0
Diamond|A| 2 (V)

0.5
10 -2

S z(a.u.)

10 -1

Dichroic mirror

P out
25mK

P in

0.0
10 -3

AWG

0

200

400
Time (ns)

600

Gain

Optical intensity

Loss

Optical intensity

H. Mashiko, Y. Chisuga, I. Katayama, K. Oguri, H. Masuda, J. Takeda, and H. Gotoh, Nature Commun. 9,1468 (2018).

F. Böhm, T. Inagaki, K. Inaba, T. Honjo, K. Enbutsu, T. Umeki, R. Kasahara, and H. Takesue,
Nature Commun. 9, 5020 (2018).

1.0
0.8
0.6

Boundary
16 cavities

24 cavities

0.4 Topological

Trivial

0.2
0.0
0

10

0.4

40

Boundary

0.8
0.6

30

20

1.0

28 cavities

12 cavities

Topological

Trivial

0.2
0.0
0

10

20

30

Cavity index

40

Superradiant emission of microwave light in a hybrid system

Controllable photonic topological insulator and boundary edge states

Superradiant Emission in a Hybrid Quantum
SystemPhotonic Topological Insulator Induced by
Optical Gain and Loss

Superradiance is a fundamental collective effect whereradiation is amplified by the coherence of multiple emitters.
Here, we explored superradiance in the fast cavity limit byusing a system composed of a three-dimensional lumped
element resonator inductively coupled to an inhomogeneously
broadened ensemble of nitrogen–vacancy centers. We observea superradiant pulse being emitted a trillion times faster thanthe decay for an individual nitrogen–vacancy center. Thisfinding was further confirmed by the nonlinear scaling of
the emitted radiation intensity with respect to the ensemble
size. Our work provides the foundation for future quantum
technologies including solid- state superradiant masers.

A photonic topological insulator is an artificial material thatis optically insulating inside but has peculiar photonic states
immune to structural disorder on its surface (topologicaledge states). However, the presence or absence of robustedge states (photonic topology) is determined by the device
structure, and hence, it has been difficult to change. We havetheoretically found a scheme to create and control a onedimensional photonic topological insulator based on a coupledlaser array, solely by changing the optical gain and loss byelectrical means. This enables us to control the location andnumber of edge states in the single array, and it thereby paves
the way to novel technologies for reconfigurable and robust
photonic topological circuits.

A. Angerer, K. Streltsov, T. Astner, S. Putz, H. Sumiya, S. Onoda, J. Isoya, W. J. Munro, K. Nemoto, J.
Schmiedmayer, and J. Majer, Nature Phys. 14, 1168 (2018).

K. Takata and M. Notomi, Phys. Rev. Lett. 121, 213902 (2018).

11

Achievements in 2018150

Nanophotonics Center

Photo-current [µA]

Nanophotonics Center

Statics

Photonic crystal

Conventional
detector range

Optical power
[µW]
100

50

0
−1.0

Nano-detector Buried absorber
range"Solar-cell mode"
p-InP

107

n-InP

67
42
26
16
6

Optical input−0.5
0Bias voltage [V]

+0.5

1 µm

Dynamics
40 Gbit/s
Photonic-crystal nano-detector operating fast in solar-cell mode

Overview
T h e N a n o p h oto nic s C e nte r was esta blis h e d in A p ril
2 012 a n d i s c o m p o s e d o f s e v e r a l g r o u p s i n v o l v e din nanophotonics research at NT T Basic Research
L a b o rato ries a n d N T T D evic e Te c h n olog y L a b o rato ries .
We are conducting studies of photonic crystals to reduce
the footprint and energy consumption of various photonic
d evices , such as o ptical switches , o ptical memories ,modulators , lasers , and photo - detectors . We are also
studying various photonic nanostructures to greatly enhancelight-matter interactions, and exploiting photonic integrated
circuits and devices for on-chip signal processing.
Extreme enhancement of light-matter interactions by using photonic
crystals and plasmonics● Integrable nanophotonic devices with extremely small energy
consumption● Nano-imprint, SPM lithography and manipulation● Integration of various high-performance devices on a silicon platform

Efficient and Fast Nano-photonic Detector
Operating in Solar-cell Mode
Conventional photodetectors (PDs) convert an optical signal
into a current by extracting photo-generated electron-hole pairs
with a reverse bias voltage. On the other hand, a photonic
crystal nanostructure allows one to fabricate nano-scale PDs
that can be used to form optical waveguides, absorbers, and pnjunctions with extremely small dimensions. This enables such“nano-PDs”to operate without degradation of photo-current
and at high speed even in the forward voltage range, which isused in solar cells. These PDs require only a small amount of
optical energy and do not use any electrical energy, giving themexcellent prospects for optical communications, especially in
dense photonic networking and computing on a CMOS chip.

●

K. Nozaki, S. Matsuo, T. Fujii, K. Takeda, A. Shinya, E. Kuramochi, and M. Notomi, APL Photonics 3,046101 (2018).

Research Center for Theoretical Quantum Physics
R e s e a rc h C e n t e r f o r T h e o re t i c a l Q u a n t u m P h y s i c s

Overview
The twentieth century saw the discovery of quantum mechanics, a setof principles that explains the nature of matter and light at the atomic
level. These counter-intuitive principles have not only dramaticallychanged our understanding of the reality of our physical world but
also enabled a technological revolution. They are responsible forthe digital age in which we live. Naturally arising questions are whatfurther can we learn from these principles and what technologicaladvances could be enabled. The newly formed Center for Theoretical
Quantum Physics established in July 2017 brings together diverse
researchers (physicists, computer scientists, mathematicians andeven chemists) from across NTT to pursue cutting edge research in ahighly collaborative environment.
The foundation of quantum mechanics
Quantum matter (hybrid quantum systems, strongly correlated systems,
condensed matter and superconducting systems)● Quantum algorithms and complexity● Quantum communication, simulation and computation● Quantum metrology and sensing● Atomic, molecular and optical physics●●

Schematic illustration of a quantum teleportation based magnetic field sensor.

Quantum Metrology Beyond the Classical
Limit under the Effect of Dephasing
It is well known that the sensitivity of classical sensors
increases with the square root of the measurement time T. A
quantum sensor, on the other hand, can in principle achievea sensitivity scaling linearly with T under ideal conditions.
However, quantum sensors are susceptible to environmental
noise, and it has remained unclear whether they can reach
their ideal sensitivity under realistic circumstances. Here, we
propose to use quantum teleportation to suppress environmental
noise of quantum sensors, which in turn allows us to show thatthe sensitivity can increase linearly with T under dephasing
effects (a typical noise source). Our scheme paves the way forrealizing ultra-sensitive quantum enhanced sensors.

Y. Matsuzaki, S. Benjamin, S. Nakayama, S. Saito, and W. J. Munro, Phys. Rev. Lett. 120, 140501(2018).

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NTT Fellow

The title of "NTT Fellow" is reserved for our most gifted scientist and engineers whose
research and development activities have brought them significant distinction bothwithin NTT and internationally. Our "Fellows" are extremely highly regarded. Next the

Medicine, Physiology, Biomedical interface & data analysis

title of "Senior Distinguished Researcher" is given to outstanding individuals who haveestablished themselves as global intellectual leaders of their own research areas. The

Shingo Tsukada"Distinguished Researcher" title is given to innovative researchers whose impressive
achievement has been recognized both within and outside NTT.
They all are responsible for leading innovative research and cutting-edge technicaldevelopments in research areas considered important to NTT.
D e c e m b e r 31 , 2018

Senior Distinguished Researcher

Nanophotonics Center Project Manager

Quantum and Nano Device Research

Masaya Notomi

Hiroshi Yamaguchi

Koji Muraki

Research Subject

Biological Information Elucidation
Using Advanced Medical Materials

Research Subject

Research Subject

Research Subject

Photon Manipulation in Photonic

Nano-mechanics inElectron Correlation in

Nanostructures

Semiconductors

Semiconductor Nanostructures

Physical Science Laboratory Executive Manager

Research Center for Theoretical Quantum Physics Project Manager

Akira Fujiwara

William John Munro

Hiroki Takesue

Research Subject

Research Subject

Research Subject

Ultimate Electronics Using

The Design of Quantum Interfaces

Quantum Communication

Semiconductor Nanostructures& Quantum Repeaters

Experiments in Telecommunication
Band
Coherent Ising Machine

Distinguished
Researcher

Norio Kumada
Katsuhiko Nishiguchi

Shiro Saito
Haruki Sanada
Imran Mahboob Kazuhide Kumakura

Kengo Nozaki Hiroki Mashiko
Koji Azuma
Yuko Ueno

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Publication List（）
…The average IF2017 for all research papers from NTT Basic Research Laboratories is 7.307
The number of papers published in international journals in 2018 is 95.

PHYSICAL REVIEW LETTERS（8.839）

10
9

APPLIED PHYSICS LETTERS（3.495）
7

NATURE COMMUNICATIONS（12.353）

7

JAPANESE JOURNAL OF APPLIED PHYSICS（1.452）
6

PHYSICAL REVIEW B（3.813）

6

PHYSICAL REVIEW A（2.909）
5

APPLIED PHYSICS EXPRESS（2.555）
NATURE（41.577）

3

NPJ QUANTUM INFORMATION（9.206）

3
3

QUANTUM SCIENCE AND TECHNOLOGY（―）
NATURE PHYSICS（22.727）

2

PHYSICAL REVIEW APPLIED（4.782）

2

SCIENTIFIC REPORTS（4.122）

2

OPTICS EXPRESS（3.356）

2
2

PHYSICAL REVIEW MATERIALS（―）
NATURE MATERIALS（39.235）

1

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY（14.357）

1

NANO RESEARCH（7.994）

1

ADVANCED OPTICAL MATERIALS（7.430）

1

CARBON（7.082）

1

NEW JOURNAL OF PHYSICS（3.579）

1
1

NANOTECHNOLOGY（3.404）
1

2

3

4

5

6

4

IEEE Fellow

For Contributions to Silicon Single-electron Devices

193

46

Akira Fujiwara

Coherent Ising Machine: a Photonic Ising Model Solver Based on Degenerate Optical Parametric Oscillator Network

International Symposium on Compound Semiconductors (ISCS) - Quantum Device Award -For Leading Contributions to the Development of Compound Semiconductor Opto/Electromechanical Systems

Hiroki Takesue

Hiroshi Yamaguchi

The Young Scientists’Prize, the Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology
Semiconductor Characterized by Isolated Attosecond Pulse

Hiroki Mashiko

The Young Scientists’Prize, the Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology
Electron Dynamics in Quantum Hall Systems

Masayuki Hashisaka

Nanotechnology Platform Japan, Major results of 2017
Charge Dynamics in Quantum Hall Edge Channels

Masayuki Hashisaka, Koji Muraki, Toshimasa Fujisawa

Information Technology Standards Commission of Japan, Contribution Award for Standardization
Contribution to the Standardization

Toshimori Honjo

The Institute of Electronics, Information and Communication Engineers (IEICE), Magazine Article Award

Development and Practical Application of a Functional Material "hitoe" that Enables Measurement of Biological Information by Simply Wearing
Nahoko Kasai, Takayuki Ogasawara, Hiroshi Nakashima, Shingo Tsukada

Encouragement award in the 42th laser society of Japan

Petahertz Electron Manipulation with Wide-bandgap Semiconductor

Hiroki Mashiko

The Japan Society of Applied Physics, Young Scientist Presentation Award
Chemical Vapor Deposition Growth of Uniform Monolayer Hexagonal Boron Nitride

Wang Shengnan, Dearle Alice, Hibino Hiroki, Kumakura Kazuhide

The Japan Society of Applied Physics, Young Scientist Presentation Award

Reconstruction of Micro-scale Tissues in Self-folded Micro-rolls
Tetsuhiko Teshima, Hiroshi Nakashima, Yuko Ueno, Satoshi Sasaki, Calum Henderson, Shingo Tsukada

The Japan Society of Applied Physics (JSAP) Young Scientist Presentation Award
Enhancement of Graphene Absorption in Plasmonic Waveguides with 30 x 20 nm2 Core

Masaaki Ono

The Japan Society of Applied Physics (JSAP) Young Scientist Presentation Award
Evanescent Coupling Between an Optical Microbottle and an Electromechanical Resonator

Motoki Asano

The Japan Society of Applied Physics (JSAP) Poster Award

Neuronal Growth Control Using Chemical Modification of Nanopillars
Nahoko Kasai, Aya Tanaka, Tetsuhiko Teshima, Koji Sumitomo, Hiroshi Nakashima

The Japan Society of Applied Physics (JSAP) Poster Award

Tuning of Plasmonic Reflection in Graphene by Carrier Density Modulation
Makoto Takamura, Norio Kumada, Shengnan Wang, Kazuhide Kumakura, Yoshitaka Taniyasu

Society for Chemistry and Micro-Nano Systems (CHEMINAS) CHEMINAS Poster Award

Direction of Topological Defects in Cell Population by Computer-aided Design of Geometrical Boundaries
Hiroki Miyazako, Tetsuhiko Teshima, Yuko Ueno

Research Institute of Electrical Communication, Tohoku University, RIEC Award

10

Number of Patents

IEEE Distinguished Lecturer Award

Petahertz Optical Drive with Wide-bandgap

9

Number of Presentations（60 Invited talks）

List of Award Winners

8

Research on Advanced Quantum State Engineering of Single Photons for Quantum Information Technologies

Nobuyuki Matsuda

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