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Optimal Thermoelectric Power Factor of Narrow-Gap Semiconducting Carbon Nanotubes with Randomly Substituted Impurities J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-03-03 Manaho Matsubara; Kenji Sasaoka; Takahiro Yamamoto; Hidetoshi Fukuyama
We have theoretically investigated thermoelectric (TE) effects of narrow-gap single-walled carbon nanotubes (SWCNTs) with randomly substituted nitrogen (N) impurities, i.e., N-substituted \((20,0)\) SWCNTs with a band gap of 0.497 eV. For such a narrow-gap system, the thermal excitation from the valence band to the conduction band contributes to its TE properties even at the room temperature. In this
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Effect of Microwave Cavity-Mode Properties on Cavity-Magnon Coupling Strength J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-03-03 Takayuki Suzuki
Recently, the cavity-magnon-polariton (CMP) system as a quasiparticle has been attracting attention because of its potential application in quantum information devices and axion detectors and as a new frontier in quantum physics. The achievement of strong interaction and its control have been extensively researched. The conventional strategy for achieving this mainly involves increasing the magnon
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de Haas–van Alphen Effect in Pressure-Induced Superconductor CrAs J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-03-01 Jun Kaneyoshi; Takeo Yoshinaga; Eiichi Matsuoka; Hisashi Kotegawa; Hideki Tou; Hishiro T. Hirose; Taichi Terashima; Shinya Uji; Hitoshi Sugawara
We report on the first observation of the de Haas–van Alphen (dHvA) effect in CrAs under hydrostatic pressures of up to 2.2 GPa, exceeding the critical pressure Pc ∼ 0.7 GPa, where the antiferromagnetic (helimagnetic) state is suppressed and the unconventional superconductivity emerges. The small Fermi surface (FS) with the dHvA frequency F of 220 T and the cyclotron effective mass \(m_{\text{c}}^{*}\)
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Charging Effects on the Adsorption and Diffusion of Au Adatoms on MgO(100) J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-26 Jong Hwan Park; Jeong Woo Yang; Min Gyo Byun; Nong Moon Hwang; Jinwoo Park; Byung Deok Yu
By ab initio calculations, the adsorption and diffusion properties of positively charged Au+ and negatively charged Au− adatoms on defect-free MgO(100) surfaces were investigated and compared with the case of charge-neutral Au0 on MgO(100). Our results showed that the most stable adsorption site of Au+ on MgO(100) is atop the O site, as per Au0, whereas that of Au− on MgO(100) is atop the Mg site.
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Scaling Relation between Electrochemical Seebeck Coefficient for Fe2+/Fe3+ in Organic Solvent and Its Viscosity J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-26 Dai Inoue; Hideharu Niwa; Hiroaki Nitani; Yutaka Moritomo
The temperature coefficient α (= dV/dT) of the redox potential (V) in a redox system, or so-called electrochemical Seebeck coefficient, is a key parameter for thermal energy harvesting. We systematically investigated α for Fe2+/Fe3+ in 16 organic solvents, i.e., 8 protic and 8 aprotic solvents. We found that α shows remarkable solvent dependence and is distributed from 0.14 mV/K for glycerin to 3.60
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Bulk–Boundary Correspondence in a Non-Hermitian Chern Insulator J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-25 Yositake Takane
A scenario of non-Hermitian bulk–boundary correspondence proposed for one-dimensional topological insulators is adapted to a non-Hermitian Chern insulator to examine its applicability to two-dimensional systems. This scenario employs bulk geometry under a modified periodic boundary condition and boundary geometry under an open boundary condition. The bulk geometry is used to define a topological number
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Transition Behavior in Silicone-coated Sand Mixtures J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-22 Marie Tani; Honoka Fujio; Rei Kurita
Granular media with a small amount of liquid possess a significant stiffness caused by interactions or capillary bridges compared to the same system when dry. Recently, another type of interacting sand where each grain is coated by silicone-oil is produced. However, macroscopic physical properties of such systems are not yet understood. In this work, we mixed the silicone-coated sand to uncoated one
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Effective Ruderman–Kittel–Kasuya–Yosida-like Interaction in Diluted Double-exchange Model: Self-learning Monte Carlo Approach J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-19 Hidehiko Kohshiro; Yuki Nagai
We study the site-diluted double-exchange (DE) model and its effective Ruderman–Kittel–Kasuya–Yosida-like interactions, where localized spins are randomly distributed, with the use of the Self-learning Monte Carlo (SLMC) method. The SLMC method is an accelerating technique for Markov chain Monte Carlo simulation using trainable effective models. We apply the SLMC method to the site-diluted DE model
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Superconductivity in the Topological Nodal-line Semimetal NaAlSi J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-19 Takahiro Yamada; Daigorou Hirai; Hisanori Yamane; Zenji Hiroi
NaAlSi is an sp electron superconductor crystallizing in a layered structure of the anti-PbFCl type with a relatively high transition temperature Tc of ~7 K. Recent electronic state calculations revealed the presence of topological nodal lines in the semimetallic band structure, which attracted much attention owing to the superconductivity. However, experimental investigation remained limited because
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Magnetization Process in EuCo2P2 and EuT2Ge2 (T: transition metal): Comparison of Experiment and Theory J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-18 Tetsuya Takeuchi; Time Tahara; Takanori Kida; Yasuo Narumi; Masayuki Hagiwara; Koichi Kindo; Wataru Iha; Yousuke Ashitomi; Tomoyuki Yara; Miho Nakashima; Yasushi Amako; Masato Hedo; Takao Nakama; Yoshichika Ōnuki
We grew single crystals of EuCo2P2 and EuT2Ge2 (T: Co, Rh, Ir, Ni, and Pd) by the Bridgman method and Sn- and In-flux methods, and studied their magnetic properties by measuring the specific heat, magnetic susceptibility, and magnetization with the magnetic field parallel to the tetragonal [100] and [001] directions. The anisotropic magnetization curves of these compounds were found to be explained
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Theoretical Analysis of the Dynamical Effects of the Amino Acid Residue Replacement in the Vicinity of the [4Fe–4S] Proximal Cluster on the O2-Tolerance of [NiFe]-Hydrogenases J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-17 Ryu-ichiro Terada; Jiyoung Kang; Masaru Tateno
Hydrogenases are enzymes that catalyze the reversible reaction, \(\text{H}_{2} \rightleftharpoons 2\text{H}^{ + } + 2\text{e}^{ - }\), that occurs at the transition metal cluster in the catalytic center (e.g., [NiFe]). The catalytic activity of most standard hydrogenases is degraded by O2 under aerobic conditions (O2-sensitivity). However, the standard hydrogenase from Citrobacter sp. S-77 (termed
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Scanning Transmission Electron Microscopy Simulation for Multi-Domain Barium Titanate J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-17 Kaita Fukao; Yukio Sato; Ryo Teranishi; Kenji Kaneko
Scanning transmission electron microscopy (STEM) allows detailed atomic displacements in ferroelectrics to be studied. Although the interpretation of the displacements is straightforward for single-domain structures, it is complicated when multiple domains are present in the direction of the electron beam. In the present study, we simulated STEM images to obtain insight into the observed ionic displacements
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Nonlinear Periodic Ion Acoustic Waves in a Relativistic Plasma with Isothermal Electrons and Cold Ions J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-17 Safeer Sadiq; Shahzad Mahmood; Qamar-ul-Haque
Propagation of nonlinear ion acoustic waves in a relativistic electron–ion plasma is studied using the covariant formulation. Ions are assumed cold and a polytropic equation of state of the form p = CnΓ is assumed for electrons with Γ = 1 (isothermal case). The continuity, momentum and energy equations for electrons and ions are transformed to a special frame of reference via Lorentz-transformation
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Uniqueness of Ground State in the Edwards–Anderson Spin Glass Model J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-17 Chigak Itoi
It is proven rigorously that the ground state in the Edwards–Anderson spin glass model is unique in any dimension for almost all continuous random exchange interactions under a condition that a single spin breaks the global \(\mathbb{Z}_{2}\) symmetry. This theorem implies that replica symmetry breaking does not occur at zero temperature. The site- and bond-overlap are concentrated at their maximal
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Growth of Fe Islands on Clean and Ammonia-saturated Si(111)7 × 7 Surfaces Studied by in situ Electron Diffraction J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-16 Liliany Noviyanty Pamasi; Shota Nishida; Shohei Takemoto; Ken Hattori
We investigated the epitaxial growth of Fe islands on clean and ammonia-saturated Si(111)7 × 7 surfaces by reflection high-energy electron diffraction for 0–10 monolayer Fe coverage. From the profile analyses of transmission electron diffraction spots of Fe crystalline islands, we found that the islands grew at a lower speed, with a larger and a smaller height on the ammonia-saturated surfaces indicating
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Cooperative Effects of a Parity-check Code on the Simultaneous Restoration of Two Images J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-16 Satoshi Kawaguchi
In this study, we consider the simultaneous image restoration of two original images. We propose a model and examine the stationary state and dynamical properties of image restoration. To restore two images simultaneously, we assume that their parity-check code is composed of two pixels: one selected from the first image and the other from the second image. For the stationary state, we apply the replica
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Momentum-Dependent Local Ansatz Approach to the Metallic Ferromagnetism J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-15 Yoshiro Kakehashi
The first principles momentum dependent local ansatz wavefunction method (MLA) has been extended to the ferromagnetic state by introducing spin-dependent variational parameters. The theory is applied to the ferromagnetic Fe, Co, and Ni. It is shown that the MLA yields the magnetizations being comparable to the results obtained by the generalized gradient approximation (GGA) in the density functional
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Evidence for 4D XY Quantum Criticality in 4He Confined in Nanoporous Media at Finite Temperatures J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-12 Tomoyuki Tani; Yusuke Nago; Satoshi Murakawa; Keiya Shirahama
4He confined in nanoporous media is a model Bose system that exhibits quantum phase transition (QPT) by varying pressure. We have precisely determined the critical exponent of the superfluid density of liquid 4He in porous Gelsil glasses with pore size of 3.0 nm using the Helmholtz resonator technique. The critical exponent ζ of the superfluid density was found to be 1.0 ± 0.1 for the pressure range
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Open Quantum Dynamics Theory for Non-Equilibrium Work: Hierarchical Equations of Motion Approach J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-10 Souichi Sakamoto; Yoshitaka Tanimura
A system–bath (SB) model is considered to examine the Jarzynski equality in the fully quantum regime. In our previous paper [J. Chem. Phys. 153, 234107 (2020)], we carried out “exact” numerical experiments using hierarchical equations of motion (HEOM) in which we demonstrated that the SB model describes behavior that is consistent with the first and second laws of thermodynamics and that the dynamics
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Possible Pressure-Induced Charge-Density Wave Quantum Critical Point in LuPd2In J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-09 M. O. Ajeesh; Thomas Gruner; Christoph Geibel; Michael Nicklas
We investigated the effect of application of hydrostatic pressure on the charge-density wave (CDW) state in Lu(Pt1−xPdx)2In by electrical-resistivity measurements. In Lu(Pt0.7Pd0.3)2In we find an increase of the CDW transition temperature upon application of pressure, which is not expected based on simple volume arguments, but in line with results of a theoretical work by Kim et al. [Phys. Rev. Lett
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Paramagnetic Effects of j-electron Superconductivity and Application to UTe2 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-08 Kozo Hiranuma; Satoshi Fujimoto
The putative spin-triplet superconductor UTe2 has an Ising-like magnetic anisotropy, indicating the Cooper pair spins parallel to the easy-axis. However, the upper critical field for the hard-axis direction is much larger than that for the easy-axis, implying the strong suppression of the Pauli depairing effect even for the hard-axis direction. This observation is consistent with the recent NMR measurements
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Polarization Dependent Bulk-sensitive Valence Band Photoemission Spectroscopy and Density Functional Theory Calculations: Part II. 4d Transition Metals J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-08 Shigenori Ueda; Ikutaro Hamada
Bulk-sensitive X-ray polarization dependent valence band photoelectron spectra of the 4d transition metals (TMs) of Y, Zr, Nb, Mo, Ru, Rh, Pd, and Ag were measured with hard X-ray photoelectron spectroscopy (HAXPES). The valence band spectral shapes of 4d TMs were modified by the X-ray polarization, but the changes of the spectral shapes of the 4d TMs were smaller than those of the 3d TMs [S. Ueda
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An Evaluation of Localized Heat Flux Associated with the Streamer at the Onset of Type-III ELMs on HL-2A Tokamak J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-08 Kimitaka Itoh; Yusuke Kosuga; Jun Cheng; Jiaqi Dong; Kaijun Zhao; Sanae-Inoue Itoh
A method is discussed to evaluate the localized radial heat flux, which is associated with the streamer, based on the observed temperature perturbation at the onset of Type-III ELMs in HL-2A tokamak. Treating the observed temperature perturbation of the streamer as a given parameter, its impact on energy flux in the core plasma is discussed. It is found that the observed streamer can have an important
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Analysis of Capacitive Power Transfer System with LCLC Compensation Network J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-05 Rui Yang; Yanzhou Sun; Jianghua Yu; Yining Sun; Mengfei Zhang
To realize the optimal output efficiency of the double-side LCLC symmetric compensation capacitive power transfer system, firstly the analytical relationships among the output power, efficiency and the variable parameters are established by using circuit theory. Secondly, the output power and efficiency of the system and the variation laws of each parameter are analyzed in detail through simulation
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Revisiting the 63Cu NMR Signature of Charge Order in La1.875Ba0.125CuO4 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-05 Takashi Imai; Philip M. Singer; Alexandre Arsenault; Masaki Fujita
We use single crystal 63Cu NMR techniques to revisit the early 63Cu NQR signature of charge order observed for La1.875Ba0.125CuO4 (Tc = 4 K) [A. W. Hunt et al., Phys. Rev. Lett. 82, 4300 (1999)]. We show that the growth of spin correlations is accelerated below ∼80 K, where the inverse Laplace transform (ILT) T1 analysis of the 139La NMR spin–lattice relaxation curve recently uncovered emergence of
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Terahertz-Field-Induced Changes of Electronic States Associated with a Polarization Modulation in BiFeO3 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-05 Naoki Sono; Yuto Kinoshita; Noriaki Kida; Toshimitsu Ito; Hiroshi Okamoto; Tatsuya Miyamoto
We performed terahertz-pulse-pump second-harmonic-generation (SHG)-probe and optical-reflectivity-probe measurements on a single crystal of a displacive-type ferroelectric, BiFeO3, to achieve an ultrafast control of the optical response by a terahertz pulse. By an application of a terahertz pulse with the amplitude of about 200 kV/cm along the polarization direction, the SHG intensity was modulated
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Magnetic and Electronic Properties of Single Crystals of Perovskite Nickelate Oxide LaNiO3 Prepared by the Laser Diode Floating Zone Method J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-04 Yasuhide Tomioka; Toshimitsu Ito; Erika Maruyama; Shinji Kimura; Isamu Shindo
Using the laser diode floating zone method, single crystals of LaNiO3, a nickel oxide with perovskite structure, have been successfully prepared under a high oxygen pressure of 4 MPa (40 bar). Single crystal x-ray diffraction indicates that the crystal structure is rhombohedral with an Ni–O–Ni bond angle of 165.3(5)°. The resistivity ρ below 30 K obeys the Fermi liquid behavior, expressed as ρ(T) =
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Bayesian Integration for Hamiltonian Parameters of X-ray Photoemission and Absorption Spectroscopy J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-03 Yuichi Yokoyama; Takayuki Uozumi; Kenji Nagata; Masato Okada; Masaichiro Mizumaki
X-ray photoemission spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) are powerful techniques for revealing Hamiltonian parameters in strongly correlated electron systems. XPS and XAS spectra contain complementary information about the electronic states, meaning that the integrated analysis of XPS and XAS is important for examining the Hamiltonian parameters. In previous research, integrated
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Perfect Transmission and Perfect Reflection of Bogoliubov Quasiparticles in a Dynamically Unstable Bose–Einstein Condensate J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-03 Terumichi Ohashi; Yuki Kawaguchi
The Nambu–Goldstone (NG) mode in a Bose–Einstein condensate (BEC) transmits a potential barrier with probability 1 in the zero-energy limit, which is known as the anomalous tunneling. In this paper, we investigate the tunneling properties of quasiparticles in a dynamically unstable BEC. We prepare a multicomponent BEC (binary and spin-1 BECs) in a dynamically unstable state and solve the tunneling
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Fast Bayesian Deconvolution Using Simple Reversible Jump Moves J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-03 Koki Okajima; Kenji Nagata; Masato Okada
We propose a Markov chain Monte Carlo-based deconvolution method designed to estimate the number of peaks in spectral data, along with the optimal parameters of each radial basis function. Assuming cases where the number of peaks is unknown, and a sweep simulation on all candidate models is computationally unrealistic, the proposed method efficiently searches over the probable candidates via trans-dimensional
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Configurational Geometry Bridges Equilibrium Structure Information from a Single to Multiple Compositions for Binary Discrete Systems J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-02 Shouno Ohta; Ryogo Miyake; Koretaka Yuge
For substitutional alloys typically referred to as classical discrete systems under constant composition, a set of microscopic states dominantly contributing to thermodynamically equilibrium structure should depend on temperature and energy through the Boltzmann factor, exp(−βE). Despite this fact, our recent study finds a set of special microscopic states that can characterize equilibrium macroscopic
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Magnetic-Field-Driven Antiferromagnetic Domain Wall Motion J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-02 Jotaro J. Nakane; Hiroshi Kohno
We theoretically study the antiferromagnetic domain wall motion actuated by an inhomogeneous external magnetic field. The Lagrangian and the equations of motion of antiferromagnetic spins under an inhomogeneous magnetic field are derived, first in terms of the Néel vector, and then using collective coordinates of the domain wall. A solution is found that describes the actuation of a domain wall by
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Mixed-Valence Ion Model for Incoherent Metallic State in Heavy-Fermion Spinel LiV2O4 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-02 Masashige Onoda
For the incoherent metallic state in the heavy-fermion spinel LiV2O4, structural and magnetic properties are explored from the viewpoint of a mixed-valence ion system consisting of localized spin-1 V3+ and spin-1/2 V4+ that may be related to the nondegenerate state of the itinerant electron system. On the basis of precise atomic coordinates including anisotropic displacement parameters, the mixed-valence
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Total Internal Reflection in an Absorbing Medium J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-02 Koichi Katsumata
We report the results of a rigorous calculation on the total internal reflection when the second medium is absorbing. A complex dielectric constant given by, \(\hat{\varepsilon }^{\text{Re}} + i\hat{\varepsilon }^{\text{Im}}\) is introduced to represent the effect of the absorption. Starting from Maxwell’s equations, we show that the angle of refraction becomes progressively smaller than \(\frac{\pi
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Room Temperature Thermoelectric Properties of Isostructural Selenides Ta2PdS6 and Ta2PdSe6 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-02 Akitoshi Nakano; Urara Maruoka; Fumiaki Kato; Hiroki Taniguchi; Ichiro Terasaki
We have measured thermoelectric properties of Ta2PdX6 (X = S, Se) around room temperature using single crystal samples. We find that the power factor of Ta2PdX6 is relatively high from middle-low to room temperatures, and notably Ta2PdSe6 shows the largest power factor among thermoelectric materials with an electrical conductivity of 10−2 Ω cm at 300 K. Ta2PdS6 will be a possible candidate for a Peltier
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Experimental Confirmation of Massive Dirac Fermions in Weak Charge-Ordering State in α-(BEDT-TTF)2I3 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-01 Kenta Yoshimura; Mitsuyuki Sato; Toshihito Osada
The electronic structure of weak charge-ordering (CO) state just below the critical pressure in an organic conductor α-(BEDT-TTF)2I3 was experimentally investigated using peak structure in the temperature dependence of interlayer magnetoresistance (MR). Based on a minimal model considering multiple Landau levels (LLs), we discuss herein the MR peak as characteristic to multilayer massless/massive Dirac
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Hybrid Quantum-Classical Algorithms and Quantum Error Mitigation J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-02-01 Suguru Endo; Zhenyu Cai; Simon C. Benjamin; Xiao Yuan
Quantum computers can exploit a Hilbert space whose dimension increases exponentially with the number of qubits. In experiment, quantum supremacy has recently been achieved by the Google team by using a noisy intermediate-scale quantum (NISQ) device with over 50 qubits. However, the question of what can be implemented on NISQ devices is still not fully explored, and discovering useful tasks for such
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Pattern Formation Simulated by an Ising Machine J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-29 Kanon Mukai; Kazue Kudo
In a ferromagnetic Ising system, domain pattern formation, i.e., phase-ordering, occurs after a sudden quench. We propose the method to simulate the pattern formation dynamics by an Ising machine. We demonstrate that the method reproduces domain patterns similar to those simulated by the Monte Carlo method. Moreover, the same domain growth law is observed in the proposed method and the Monte Carlo
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Formation of Single Polar Domain in α-Cu2V2O7 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-29 Pharit Piyawongwatthana; Daisuke Okuyama; Kazuhiro Nawa; Kittiwit Matan; Taku J. Sato
We revisited the crystal structure of α-Cu2V2O7. An absolute structure determination have been performed. Ten pieces of crystals were randomly selected from a single large crystal. Inclusion of inversion domain was evaluated by estimating the Flack parameter. All the measured crystals have zero Flack parameters within the standard uncertainty. Relative intensity \(I(14\ 2\ 2)/I(14\ 2\ \bar{2})\) on
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Analysis of Glass Behavior of Lu2Fe3O7 with Distributed Equivalent Circuit Model J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-29 Yukimasa Fukada; Ryota Fukuyama; Kosuke Fujiwara; Kenji Yoshii; Kei Shigematsu; Masaki Azuma; Naoshi Ikeda
We report an analysis of the dielectric glasslike state of the spin- and charge-ordered system Lu2Fe3O7, which has structural and physical properties analogous to those of the electronic ferroelectrics RFe2O4 (R: rare earth). Aging and memory effects of resistivity were found in the electric impedance response. We performed a numerical analysis with equivalent electric circuits that have a logarithmic
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Large Zeeman Splitting in Out-of-Plane Magnetic Field in a Double-Layer Quantum Point Contact J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-29 Daiju Terasawa; Shota Norimoto; Tomonori Arakawa; Meydi Ferrier; Akira Fukuda; Kensuke Kobayashi; Yoshiro Hirayama
In this study, we observe that the conductance of a quantum point contact on a GaAs/AlGaAs double quantum well depends significantly on the magnetic field perpendicular to the two-dimensional electron gas. In the presence of the magnetic field, the subband edge splitting due to the Zeeman energy reaches 0.09 meV at 0.16 T, thereby suggesting an enhanced g-factor. The estimated g-factor enhancement
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ABCD of Kondo Effect J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-28 Taro Kimura
We explore the Kondo effect incorporating the localized impurity transforming under generic symmetry group G, that we call the G-Kondo effect. We derive the one-dimensional effective model coupled with the impurity, and studied the thermodynamic properties based on the boundary conformal field theory approach. We in particular study the impurity entropy at the conformal fixed point, and the low temperature
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Tit-for-Tat Strategy as a Deformed Zero-Determinant Strategy in Repeated Games J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-27 Masahiko Ueda
We introduce the concept of deformed zero-determinant strategies in repeated games. We then show that the Tit-for-Tat strategy in the repeated prisoner’s dilemma game is a deformed zero-determinant strategy, which unilaterally equalizes the probability distribution functions of payoffs of two players.
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First Principles Investigation of Anomalous Hall and Spin Hall Effects in Ferromagnetic CoPt J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-27 Guanxiong Qu; Kohji Nakamura; Masamitsu Hayashi
The intrinsic spin Hall conductivity and the anomalous Hall conductivity of ferromagnetic L10-CoPt are studied using first principles calculations. We identify the symmetry of the Berry curvature and the spin Berry curvature to reveal the correlation between the anomalous Hall and the spin Hall conductivities. Whereas the Berry curvature preserves the C4v crystal rotation symmetry along the c-axis
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A Note on the Bilinearization of the Generalized Derivative Nonlinear Schrödinger Equation J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-27 Junchao Chen; Bao-Feng Feng
The bilinearization of the generalized derivative nonlinear Schrödinger (GDNLS) equation is investigated systematically. It is known recently that the GDNLS equation can be decomposed into two different bilinear systems under the vanishing and nonvanishing boundary condition, respectively. However, it remains a question of how these two systems are related. In this letter, we show that all the bilinear
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Functional Renormalization Group Analysis on the Spectral Function in One-Dimensional Excitonic Insulators J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-26 Moe Kaneko; Masahisa Tsuchiizu
We analyze the one-particle spectral function for the model of Ta2NiSe5 by utilizing the functional renormalization group (fRG) method. By properly accounting for one-dimensional fluctuation effects, the scattering process between the fermions in the conduction (c) and valence (f) bands becomes relevant, and there appears a bound state between the c and f fermions without any symmetry breaking in the
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Mathematical Analysis of Epidemic Disease Models and Application to COVID-19 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-22 Takeo Fujiwara
Mathematical models for infectious diseases are considered. The exact solutions of SIR model are analyzed in terms of oscillatory motion in susceptible–infected (S–I) phase space. SIR model can not apply the effect of repeated epidemics, and then, we introduce inflow population into SIR model and name it SIR-i model. Stability is analyzed around a stable equilibrium point in S–I phase space. The nature
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Interplay of Valence and Semimetal-to-Insulator Transitions in SmS J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-22 Shinji Watanabe
Recent discoveries of a new type of quantum criticality arising from Yb-valence fluctuations in Yb-based metal in periodic crystal and quasicrystal have opened a new class of quantum critical phenomena in correlated electron systems. To clarify whether this new concept can be generalized to other rare-earth-based semimetal and insulator, we study SmS which exhibits golden-black phase transition under
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Superconducting Dome Underlying Bipolaronic Insulating State in Charge-doped Ti4O7 Epitaxial Films J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-22 Takuto Soma; Tomohiro Kobayashi; Kohei Yoshimatsu; Akira Ohtomo
The bipolaronic insulating (BI) state can cause the emergent superconducting phase when the strength of electron–phonon interaction is deliberately reduced. In this report, we have investigated electronic phase diagram of the well-known BI compound Ti4O7 by analyzing the transport properties of over 40 epitaxial-film samples. The diagram captures the systematic suppression of the BI state with increasing
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Suppression of Pseudogap Behavior and Antiferromagnetic Fluctuations by Electron Doping in T′-La1.8Eu0.2CuO4−yFy Studied by 63,65Cu NMR J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-21 Masaki Watai; Yongsun Lee; Hideto Fukazawa; Yoh Kohori; Toshiki Sunohara; Kota Shiosaka; Takayuki Kawamata; Yoji Koike
We performed 63,65Cu NMR measurements of an electron-doped high-Tc cuprate superconductor T′-La1.8Eu0.2CuO4−yFy (0 ≤ y ≤ 0.125) having Nd2CuO4-type structure (so-called T′-structure). Pseudogap behavior is observed in the lightly electron-doped region of y ≤ 0.075. The nuclear spin–lattice relaxation rate 1/T1 revealed that the antiferromagnetic spin fluctuations are suppressed by electron doping.
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Emergence of Frustrated Short-Range Order above Long-Range Order in the S = 1/2 Kagome Antiferromagnet CaCu3(OD)6Cl2∙0.6D2O J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-21 Yoshihiko Ihara; Kazuki Matsui; Yoshimitsu Kohama; Sven Luther; Daryna Opherden; Jochen Wosnitza; Hannes Kühne; Hiroyuki K. Yoshida
We report on the low-energy dynamics in the kagome antiferromagnet CaCu3(OD)6Cl2∙0.6D2O (Ca-kapellasite) as studied by use of 2D-NMR measurements. Previous 35Cl-NMR measurements revealed that the nuclear spin–lattice relaxation rate (1/T1) shows two peaks at temperatures, T* = 7.2 K and Ts \( \simeq \) 25 K. While the low-temperature peak at T* is ascribed to the critical fluctuations near the long-range
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Asymmetrical Recoil of an Atom with an Optical Absorption Coefficient Depending on the Incident Direction J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-19 Norio Inui
The recoil of a neutral atom irradiated by counter-propagating light with the same frequency and intensity is studied. The expectation value of the momentum transferred from the light to the atom with spherical symmetry at rest is usually zero because of symmetry. However, if the optical absorption coefficient of the atom depends on the incident light direction due to the magnetoelectric effect, as
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Direct Observation of Cycloidal Spin Modulation and Field-induced Transition in Néel-type Skyrmion-hosting VOSe2O5 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-18 Takashi Kurumaji; Taro Nakajima; Artem Feoktystov; Earl Babcock; Zahir Salhi; Victor Ukleev; Taka-hisa Arima; Kazuhisa Kakurai; Yoshinori Tokura
We investigate the spin rotational structure of magnetic skyrmions in a tetragonal polar magnet VOSe2O5 via polarized small-angle neutron scattering (SANS). Spin polarization analysis of the scattered neutrons provides consistent evidence for the cycloidal spin modulation in all the incommensurate phases at zero and non-zero magnetic field along the c axis, including the triangular skyrmion-lattice
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Universality Class around the SU(3) Symmetric Point of the Dimer–Trimer Spin-1 Chain J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-18 Tohru Mashiko; Shunji Moriya; Kiyohide Nomura
We study critical phenomena of an SU(3) symmetric spin-1 chain when adding an SU(3) asymmetric term. To investigate such phenomena, we numerically diagonalize the dimer–trimer (DT) model Hamiltonian around the SU(3) symmetric point, named the pure trimer (PT) point. We analyze our numerical results on the basis of the conformal field theory (CFT). First of all, we discover that soft modes appear at
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Unusual Nonmagnetic Ordered State in CeCoSi Revealed by 59Co-NMR and NQR Measurements J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-18 Masahiro Manago; Hisashi Kotegawa; Hideki Tou; Hisatomo Harima; Hiroshi Tanida
We performed 59Co nuclear magnetic and quadrupole resonance (NMR and NQR) measurements under pressure on a single-crystalline CeCoSi, which undergoes an unresolved phase transition at T0. The NQR spectra clearly showed that the phase transition at T0 is nonmagnetic, but any symmetry lowering at the Co site was not seen irrespective of the feature of second-order phase transition. By contrast, the NMR
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Pump–probe Spectroscopy with Uniaxial Strain for BaV10O15 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-15 Takuo Saiki; Kazuma Funahashi; Teruo Yamazaki; Tomomasa Kajita; Takuro Katsufuji
We performed a pump–probe optical reflectivity measurement with an applied uniaxial strain for bulk single crystals of BaV10O15 at room temperature. We found that with a compressive strain of ΔL/L = −3.0 × 10−3 along the b-axis, the oscillation in the time dependence of the photoinduced reflectivity change, which arises from the propagation of shockwave, becomes longer in period, indicating that the
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Free-Energy Functional Approach to Inverse Problems for Self-Assembly of Three-Dimensional Crystals J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-15 Masashi Torikai
In this study, a variational method for the inverse problem of self-assembly, i.e., a reconstruction of the interparticle interaction potential of a given structure, is applied to three-dimensional crystals. According to the method, the interaction potential is derived as a function that maximizes the free-energy functional of the one- and two-particle density distribution functions. The interaction
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Inelastic X-ray Scattering Study of the Cage-structured Compound PrRh2Zn20 J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-14 Kazuhei Wakiya; Takahiro Onimaru; Satoshi Tsutsui; Takumi Hasegawa; Keisuke T. Matsumoto; Yu Yamane; Naohiro Nagasawa; Alfred Q. R. Baron; Norio Ogita; Masayuki Udagawa; Toshiro Takabatake
The phonon properties of the cage-structured compound PrRh2Zn20, whose electrical resistivity exhibits a hysteretic behavior between 140 and 470 K, have been studied by inelastic X-ray scattering (IXS) measurements and first-principles calculation. The IXS spectra for the [110] transverse and [111] longitudinal phonon modes show low-energy excitations at 6–7 meV, which are assigned to optical phonon
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Detailed Investigations on Short- and Intermediate-Range Structures of Ge–Se Glasses near the Stiffness Transition Composition J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-13 Shinya Hosokawa; Yukinobu Kawakita; László Pusztai; Kazutaka Ikeda; Toshiya Otomo
In order to improve the reliability of short- and intermediate-range atomic structures of GexSe1−x glasses, high quality neutron diffraction data, in both the real and reciprocal spaces, were added to the existing anomalous x-ray scattering and x-ray diffraction datasets [Hosokawa et al., Phys. Rev. B 84, 014201 (2011)] for reverse Monte Carlo modeling. This addition proved to be highly effective for
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Non-Hermitian Ferromagnetism in an Ultracold Fermi Gas J. Phys. Soc. Jpn. (IF 1.579) Pub Date : 2021-01-13 Hiroyuki Tajima; Kei Iida
We develop a non-Hermitian effective theory for a repulsively interacting Fermi gas in the excited branch. To elucidate how a metastable ferromagnetic state occurs as observed in recent experiments, we use a simplified approach based on the many-body T-matrix approximation, which successfully explains repulsive Fermi polarons in the polarized limit. The on-shell T-matrix is employed as a complex-valued