pinecone/core-2020-05-10-deduplication huggingface dataset:
First Principle Studies of B and P Doped Si Nanocrystals

The properties of n- and p-doped silicon nanocrystals obtained through ab initio calculations are reviewed here. The aim is the understanding of the effects induced by substitutional doping on the structural, electronic and optical properties of free-standing and matrix-embedded Si nanocrystals. The preferential positioning of the dopants and their effects on the structural properties with respect to the undoped case, as a function of the nanocrystals diameter and termination, are identified through total-energy considerations. The localization of the acceptor and donor related levels in the band gap of the Si nanocrystals, together with the impurity activation energy, are discussed as a function of the nanocrystals size. The dopant induced differences in the optical properties with respect to the undoped case are presented. Finally, the case of B and P co-doped nanocrystals is discussed showing that if carriers are perfectly compensated, the Si nanocrystals undergo a minor structural distortion around the impurities inducing a significant decrease of the impurities formation energies with respect to the single doped case. Due to co-doping, additional peaks are introduced in the absorption spectra, giving rise to a size-dependent red shift of the absorption spectra
Near-infrared photothermal response of plasmonic gold-coated
  nanoparticles in tissues

We propose a new approach to understand the time-dependent temperature
increasing process of gold-silica core-shell nanoparticles injected into
chicken tissues under near-infrared laser irradiation. Gold nanoshells strongly
absorb near-infrared radiations and efficiently transform absorbed energy into
heat. Temperature rise given by experiments and numerical calculations based on
bioheat transfer are in good agreement. Our work improves the analysis of a
recent study [Richardson et al., Nano Lett. 9, 1139 (2009)] by including
effects of the medium perfusion on temperature increase. The theoretical
analysis can also be used to estimate the distribution of nanoparticles in
experimental samples and provide a relative accuracy prediction for the
temperature profile of new systems. This methodology would provide a novel and
reliable tool for speeding up photothermal investigations and designing
state-of-the-art photothermal devices.Comment: 5 pages, 3 figures, accepted for publication in Physica Status Solidi
  A: Applications and Materials Scienc
Coherence properties and quantum control of silicon vacancy color
  centers in diamond

Atomic-scale impurity spins, also called color centers, in an otherwise
spin-free diamond host lattice have proven to be versatile tools for
applications in solid-state-based quantum technologies ranging from quantum
information processing (QIP) to quantum-enhanced sensing and metrology. Due to
its wide band gap, diamond can host hundreds of different color centers.
However, their suitability for QIP or sensing applications has only been tested
for a handful of these, with the nitrogen vacancy (NV) strongly dominating this
field of research. Due to its limited optical properties, the success of the NV
for QIP applications however strongly depends on the development of efficient
photonic interfaces. In the past years the negatively charged silicon vacancy
(SiV) center received significant attention due to its highly favourable
spectral properties such as narrow zero phonon line transitions and weak phonon
sidebands. We here review recent work investigating the SiV centre's orbital
and electron spin coherence properties as well as techniques to coherently
control its quantum state using microwave as well as optical fields and we
outline potential future experimental directions to improve the SiV's coherence
time scale and to develop it into a valuable tool for QIP applications
Chemical Vapor Deposition of Al13 Fe4 Highly Selective Catalytic Films for the Semi-Hydrogenation of Acetylene

Catalytic properties of coatings containing the Al13Fe4 intermetallic phase are tested in the reaction of semi-hydrogenation of acetylene. The selectivity to ethylene is found as high as 74% close to the reported values for pure,unsupported Al13Fe4. The initial conversion of acetylene to ethylene is 84% and rapidly drops due to the catalytic formation of carbon-based by-products on secondary Al-Fe phases. Coatings are processed through sequential chemical vapor deposition (CVD) of aluminum (5 Torr, 180 °C) and iron(40 Torr, 140 °C) layers, followed by in situ annealing for 60 min at 575 °C.Deposition proceeds at high growth rate, resulting in 15 μm thick films. After annealing, coatings are composed of the Al13Fe4 phase, co-existing with minor secondary Al-Fe intermetallic phases. Overall, it is shown that films containing complex Al-Fe intermetallic phases can be processed by CVD, opening new routes to the engineering of pure, supported Al13Fe4 catalysts on 3D or porous supports
Quantized electron transport through graphene nanoconstrictions

Here, the quantization of Dirac fermions in lithographically defined grapheme nanoconstrictions is studied. Quantized conductance is observed in single nanoconstrictions fabricated on top of a thin hexamethyldisilazane layer over a Si/SiO₂ wafer. This nanofabrication method allows to obtain well defined edges in the nanoconstrictions, thus reducing the effects of edge roughness on the conductance. The occurrence of ballistic transport is proved and several size quantization plateaus are identified in the conductance at low temperature. Experimental data and numerical simulations show good agreement, demonstrating that the smoothening of the plateaus is not related to edge roughness but to quantum interference effects
About the interaction between a laser beam and group IV nanowires: a study of the electromagnetic field enhancement in homogeneous and heterostructured nanowires

The optical properties of semiconductor nanowires (NWs) are object of study
because they are the building blocks of the future nanophotonic devices. The
high refractive index and its reduced dimension, make them suitable for
photon engineering. The study of the interaction between NWs and visible
light has revealed resonances of the light absorption/scattering by the NWs.
Micro-Raman spectroscopy is used as a characterization method of semiconductor
NWs. The relation between the Raman intensity and the incident
electromagnetic (EM) field permits to study the light/NW interaction through
the micro-Raman spectra of individual NWs. As compared to either metallic
or dielectric NWs, the semiconductor NWs add additional tools to modify its
interaction with light, for example, the composition, the presence of
heterostructures, both axial and radial, doping, and the surface morphology.
One presents herein a study of the optical response of group IV semiconductor
NWs to visible photons. The study is experimentally carried out through the micro-Raman spectroscopy of different group IV NWs, both homogeneous and heterostructured (SiGe/Si), and the results are analyzed in terms of the EM modeling of the light/NW interaction using finite element methods (FEMs). The heterostructures are seen to produce additional resonances allowing new photonic capacities to the semiconductor NWs.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref VA293U13
サンセイブンケイ　キドルイ　ダイ1　センイ　キンゾク　ケイカブツ　ノ　ゴウセイ　ト　ジキテキ　オヨビ　デンキテキ　セイシツ　二　カンスル　ケンキュウ

This is the author's version of a work that was accepted for publication in physica status solidi (a). Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in physica status solidi (a), VOLUME 70, ISSUE 1, 1982-05-16, DOI: 10.1002/pssa.2210710139This is the author's version of a work that was accepted for publication in physica status solidi (a). Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in physica status solidi (a), VOLUME 72, ISSUE 2, 1982-08-16, DOI: 10.1002/pssa.2210720250This is the author's version of a work that was accepted for publication in physica status solidi (a). Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in physica status solidi (a), VOLUME 80, ISSUE 2, 1983-12-16, DOI: 10.1002/pssa.2210800224This is the author's version of a work that was accepted for publication in physica status solidi (a). Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in physica status solidi (a), VOLUME 83, ISSUE 2, 1984-06-16, DOI: 10.1002/pssa.2210830217This is the author's version of a work that was accepted for publication in physica status solidi (a). Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in physica status solidi (a), VOLUME 87, ISSUE 1, 1985-01-16, DOI: 10.1002/pssa.2210870127H. Kido, T. Hoshikawa, M. Koizumi, M. Shimada, Crystal structure and magnetic and electrical properties of GdMSi (M = first-row transition metal), Journal of the Less Common Metals, Volume 99, Issue 1, May 1984, Pages 151-15
Thermal stability of Hg1-xMnxTe compound semiconductors

The thermal behaviour of Hg1-xMnxTe single crystals is investigated by means of the RBS/channeling technique. The stoichiometry parameter x ranges from 0.08 to 0.2. An important release of Hg atoms is observed after annealing in hydrogen atmosphere at 240 °C for 10 min. Backscattering spectra for crystals with x = 0.2 revealed quite a sharp Hg edge proceeding towards greater depth with increasing annealing temperature, the shallower region being completely depleted of Hg. Somewhat different behaviour is noticed for samples with x < 0.1. Although the Hg edge is also observed, the intensity of the Hg portion of the spectra diminishes with increasing annealing temperature or time. The latter effect is also observed for all samples after the second and further annealings. The examination by means of the optical microscopy reveals the presence of small cracks and pits which are apparently formed upon annealing. The Hg release through the crack walls is therefore responsible for the lowering of the Hg portion in the backscattering spectra.
Effect of the deposition rate on ITO thin films properties prepared by ion beam assisted deposition (IBAD) technique

Indium tin oxide (ITO) thin films have been deposited onto glass substrates at room temperature by ion beam assisted deposition technique at different deposition rates (0.1 -- 0.3 nm/s). The effects of the deposition rate on the structural, optical and electrical properties of the deposited films have been studied. The optical constants of the deposited films were calculated by fitting the transmittance spectra using the semi-quantum model. Considering the application for the electromagnetic wave shielding which needs a high IR reflectance, the optimising deposition rate is 0.2 nm/s. The films prepared at this deposition rate shows a relative high IR reflectance (60%), a good electrical conductivity (5 x 10-3 -cm), and a reasonable transmittance in the visible region (over 80%)
Experimental Study of Pressure Influence on Tunnel Transport into 2DEG

We present the concept and the results of pilot measurements of tunneling in
a system {Al/$\delta_{Si}$-GaAs} under pressure up to 2 GPa at 4.2 K. The
obtained results may indicate the following: the barrier height for
{Al/$\delta$-GaAs} equals to 0.86 eV at P=0 and its pressure coefficient is $3
meV/kbar$; charged impurity density in the delta-layer starts to drop from
$4.5\times 10^{12} cm^{-2}$ down to $3.8\times 10^{12} cm^{-2}$ at about 1.5
GPa; metal-insulator transition may occur in 2DEG at about 2 GPa
Tight-binding parameters from the full-potential linear muffin-tin
  orbital method: A feasibility study on NiAl

We have examined a method of direct extraction of accurate tight-binding
parameters from an ab-initio band-structure calculation. The linear muffin-tin
potential method, in its full-potential implementation, has been used to
provide the hamiltonian and overlap matrix elements in the momentum space.
These matrix elements are Fourier transformed to real space to produce the
tight-binding parameters. The feasibility of this method has been tested on the
intermetallic alloy NiAl, using spd orbitals for each atom. The parameters
generated for this alloy have been used as input to a real-space calculation of
the local density of states using the recursion method.Comment: 12 pages, RevTex, 5 figure
Orbital Ordering and Orbital Fluctuations in Transition Metal Oxides

We summarize some characteristic features of the frustrated magnetic
interactions in spin-orbital models adequate for cubic transition metal oxides
with orbital degeneracy. A generic tendency towards dimerization, found already
in the degenerate Hubbard model, is confirmed for $t_{2g}$ but not for $e_g$
systems. In the $t_{2g}$ case the quantum orbital fluctuations are more
pronounced and contribute to a stronger competition between different magnetic
and orbital states. Therefore the orbital liquid states exist in some undoped
$t_{2g}$ systems, while in the manganites such states can be triggered only by
doping.Comment: 9 pages, 5 figure
Stripe fractionalization II: the quantum spin nematic and the Abrikosov
  lattice

In part (I) of this two paper series on stripe fractionalization, we argued
that in principle the `domain wall-ness' of the stripe phase could persist in
the spin and charge disordered superconductors, and we demonstrated how this
physics is in one-to-one correspondence with Ising gauge theory. Here we focus
on yet another type of order suggested by the gauge theory: the quantum spin
nematic. Although it is not easy to measure this order directly, we argue that
the superconducting vortices act as perturbations destroying the gauge symmetry
locally. This turns out to give rise to a simple example of a gauge-theoretical
phenomenon known as topological interaction. As a consequence, at any finite
vortex density a globally ordered antiferromagnet emerges. This offers a
potential explanation for recent observations in the underdoped 214 system
Competition between superconductivity and the pseudogap phase in the t-J
  model

The t-J model in the large N limit (N denotes the number of spin components)
yields a pseudogap phase in the underdoped region which is related to a d-wave
charge density wave (d-CDW). We present results for the doping dependence of
the superconducting and d-CDW order parameters as well as for collective
excitations in the presence of these two order parameters. We argue that the
electronic Raman spectrum with B$_{1g}$ symmetry probes the amplitude
fluctuations of the d-CDW at zero momentum.Comment: 4 pages, 4 figures, will appear in Proc. of "Physics of Magnetism'02
Correlated hopping in infinite dimensions: Rigorous local approach

The general approach for the description of correlated hopping in the
Dynamical Mean-Field Theory which is based on the expansion over electron
hopping around the atomic limit is developed. It is formulated in terms of the
local irreducible parts (cumulants) of Green's functions and allowed to
calculate thermodynamical functions. As a limit case the Falicov-Kimball model
with correlated hopping is considered.Comment: 4 pages, 2 figures, submitted to the proceedings of the European
  Conference Physics Of Magnetism '02, July 1-5, 2002, Poznan, POLAN
Vertical and Diagonal Stripes in the Extended Hubbard Model

We extend previous real-space Hartree-Fock studies of static stripe stability
to determine the phase diagram of the Hubbard model with anisotropic
nearest-neighbor hopping t, by varying the on-site Coulomb repulsion U and
investigating locally stable structures for representative hole doping levels
x=1/8 and x=1/6. We also report the changes in stability of these stripes in
the extended Hubbard model due to next-neighbor hopping t' and to a
nearest-neighbor Coulomb interaction V.Comment: 4 pages, 2 figure
Jahn-Teller Effect and Superexchange in Half-Doped Manganites

We investigate the stability of the charge exchange (CE) phase within a
microscopic model which describes a single plane as in
La$_{0.5}$Sr$_{1.5}$MnO$_4$. The model includes Coulomb interactions (on-site
and intersite), the Jahn-Teller term and the superexchange interactions due to
$e_g$ and $t_{2g}$ electrons. By investigating the phase diagram at T=0 in
mean-field approximation we conclude that the superexchange interactions can
stabilize the CE phase, but only if they are stronger than estimated from
spectroscopy.Comment: 4 pages, 3 figure
Non-Ergodicity of the 1D Heisenberg Model

The relevance of zero-energy functions, coming from zero-energy modes and
present in the structure of bosonic Green's functions, is often underestimated.
Usually, their values are fixed by assuming the ergodicity of the dynamics, but
it can be shown that this is not always correct. As the zero-energy functions
are connected to fundamental response properties of the system under analysis
(specific heat, compressibility, susceptibility, etc.), their correct
determination is not an irrelevant issue. In this paper we present some results
regarding the zero-energy functions for the Heisenberg chain of spin-1/2 with
periodic boundary conditions as functions of the number of sites, temperature
and magnetic field. Calculations are pursued for finite chains, using equations
of motion, exact diagonalization and Lanczos technique, and the extrapolation
to thermodynamic limit is studied.Comment: 4 pages, 2 figure
Quantum and thermal effects in the double exchange ferromagnet

The physics of the ferromagnetic phase of the ``double exchange'' model has
been widely discussed in the context of the CMR manganites. Usually, the double
exchange ferromagnet is treated is classically, by mapping it onto an effective
Heisenberg model. However this mapping does not permit a correct treatment of
quantum or thermal fluctuation effects, and the results obtained lack many of
the interesting features seen in experiments on the manganites. Here we outline
a new analytic approach to systematically evaluating quantum and thermal
corrections to the magnetic and electronic properties of the double exchange
ferromagnet.Comment: 4 pages summary of results for spin excitations in DE model with a
  few comments on associated electronic physics (from talk given at European
  Conference on Physics of Magnetism, Poznan 2002
The Correlated Kondo-lattice Model

We investigate the ferromagnetic Kondo-lattice model (FKLM) with a correlated
conduction band. A moment conserving approach is proposed to determine the
electronic self-energy. Mapping the interaction onto an effective Heisenberg
model we calculate the ordering of the localized spin system self-consistently.
Quasiparticle densities of states (QDOS) and the Curie temperature are
calculated. The band interaction leads to an upper Hubbard peak and modifies
the magnetic stability of the FKLM.Comment: 4 pages, 4 figure
Spin waves in La_2CuO_4: band structure and correlation effects

We calculate the antiferromagnetic spin wave dispersion in the half-filled
(electronic density n=1) Hubbard model for a two-dimensional square lattice,
using the random phase approximation (RPA) in a broken symmetry (spin density
wave) ground state. Our results for the spin wave dispersion, \omega(\vec q),
are compared with high-resolution inelastic neutron scattering performed on
La_2CuO$_4. The effects of different band structures and different values of
the on-site Coulomb interaction on the spin wave spectrum is studied.
Particular attention is put on the high energy dispersion values
\omega(\pi/2,\pi/2) and \omega(0,\pi).Comment: 4 pages, 2 figure
Some universal relations between the gap and thermodynamic functions
  plausible for various models of superconductors

It is proven that there exist some universal relations between the energy gap
and the differences of the thermodynamic potential, entropy, specific heat and
critical magnetic field for many two- and three-dimensional models of
superconductivity with spin-singlet Cooper pairs forming \textit{s} or
\textit{d} or \textit{g} etc. states. The obtained formulae make it possible to
derive thermodynamic functions and, in particular, the superconducting specific
heat and the critical magnetic induction in the whole temperature range $0\leq
T\leq T_{c}$ employing the form of $\Delta(T)$ only. The inverse formula
allowing us to find $\Delta(T)$, when the temperature dependence of the
specific heat difference is known, is also presented. The results are referred
to some obtained within the McMillan formalism, and some remarks on an
application of the present formulae to the {\textit{t--J}} model are given.Comment: 10 pages, RevTeX4, to appear in physica status solidi (b
Effect of surface tension and depolarization field on ferroelectric
  nanomaterials properties

The theory of size effects of the properties of nanocrystalline ferroelectric
ceramic or nanoparticle powder allowing for surface tension and depolarization
field is proposed. Surface tension was included into free energy functional and
surface energy was expressed via surface tension coefficient. The latter was
shown to be dependent on temperature due to its relation to dielectric
permittivity of the nanoparticles. The depolarization field effect was
calculated in the model taking into account the space charge layer on the
surface, this space-charge being able to compensate depolarization field in the
bulk material. Euler-Lagrange Equation for inhomogeneous polarization of
nanomaterial with boundary condition where extrapolation length was shown to be
temperature dependent quantity was solved analytically both in paraelectric and
ferroelectric phase of size driven phase transition. This phase transition
critical temperature dependence on the particle size was calculated.
Temperature and size dependence of nanomaterials polarization and dielectric
susceptibility was obtained. The possibility to calculate these and other
properties by minimization of conventional free energy in the form of different
power polarization series, but with the coefficients which depend on particles
size, temperature, contribution of depolarization field and surface tension
coefficient was demonstrated. These latter effects were shown to influence
essentially the nanomaterial properties. The comparison with available
experimental data is performed.Comment: 30 pages, 11 figure