Spin-Driven Ferroelectricity and Magneto-Electric Effects in Frustrated Magnetic Systems

Taka-hisa Arima — 2011-05-10T09:00:00+09:00

Authors: Taka-hisa Arima
The interplay between magnetism and electricity in matter has become a central issue of condensed-matter physics. This review focuses on the ferroelectricity induced by magnetic order mostly in frustrated magnets, which is nowadays referred to as magneto-electric (ME) multiferroic, or often only as multiferroic. Some distinct types of microscopic origins relevant to the spin-driven ferroelectricity are discussed in detail. Then one sees that the frustration-based spin-driven ferroelectrics can exhibit nonlinear and giant ME responses of phase-transition type and of domain-control type, in contrast to the conventional magnetoelectrics hosting linear ME effects.©2011 The Physical Society of Japan

Numerical-Diagonalization Study of Spin Gap Issue of the Kagome Lattice Heisenberg Antiferromagnet

Hiroki Nakano and Toru Sakai — 2011-05-10T09:00:00+09:00

Authors: Hiroki Nakano and Toru Sakai
We study the system size dependence of the singlet–triplet excitation gap in the S=1/2 kagome-lattice Heisenberg antiferromagnet by numerical diagonalization. We successfully obtain a new result of a cluster of 42 sites. The two sequences of gaps of systems with even-number sites and that with odd-number sites are separately analyzed. Careful examination clarifies that there is no contradiction when we consider the system to be gapless.©2011 The Physical Society of Japan

Linear and Non-Linear Dielectric Responses of a Model Glass Former

Takashi Odagaki, Hideaki Katoh, and Yasuo Saruyama — 2011-05-10T09:00:00+09:00

Authors: Takashi Odagaki, Hideaki Katoh, and Yasuo Saruyama
Exploiting a simple model for glass formers, we demonstrate that three characteristic temperatures, Vogel–Fulcher, glass transition and cross-over temperatures, can be determined from an analysis of the dielectric response. We define the relaxation time in three different ways and show that they diverge at different temperatures. From the analysis of linear and non-linear dielectric responses, we also show that the real part of the susceptibilities at the static limit becomes a cusp below the cross-over temperature and its curvature changes at the glass transition temperature.©2011 The Physical Society of Japan

Self-Interaction Corrected Electronic Structure and Energy Gap of CuAlO_{2} beyond Local Density Approximation

Akitaka Nakanishi and Hiroshi Katayama-Yoshida — 2011-05-10T09:00:00+09:00

Authors: Akitaka Nakanishi and Hiroshi Katayama-Yoshida
We implemented a self-interaction correction (SIC) into first-principles calculation code to go beyond local density approximation and applied it to CuAlO_{2}. Our simulation shows that the valence band width calculated within the SIC is narrower than that calculated without the SIC because the SIC makes the d-band potential deeper. The energy gap calculated within the SIC expands and is close to experimental data.©2011 The Physical Society of Japan

Traces of Z_{2}-Vortices in CuCrO_{2}, AgCrO_{2}, and PdCrO_{2}

Mamoun Hemmida, Hans-Albrecht Krug von Nidda, and Alois Loidl — 2011-05-10T09:00:00+09:00

Authors: Mamoun Hemmida, Hans-Albrecht Krug von Nidda, and Alois Loidl
The spin-spin relaxation of the two-dimensional triangular lattice antiferromagnets CuCrO_{2}, AgCrO_{2}, and PdCrO_{2} is investigated by electron spin resonance spectroscopy. The data proof excellent agreement with very recent predictions for the Z_{2}-vortex ordering scenario in triangular Heisenberg antiferromagnets derived by Okubo and Kawamura.©2011 The Physical Society of Japan

A Question on the Kohn Anomaly and Screening Effects in Pt and Pt Alloys

Yorihiko Tsunoda, Takuro Kodama, and Masakazu Nishi — 2011-05-10T09:00:00+09:00

Authors: Yorihiko Tsunoda, Takuro Kodama, and Masakazu Nishi
Phonon dispersion curves of the [110] T1 branch for pure Pt, Pt_{90}Fe_{10}, Pt_{94}Mn_{6}, and Pt_{87}V_{13} alloys were measured to study the Fermi surface effects using neutron inelastic scattering. For pure Pt, the existence of the Kohn anomaly was confirmed. For the other Pt alloys, however, the Kohn anomaly of the [110] T1 phonon branch was strongly suppressed by alloying at less than 10 at. % of 3d transition elements, although the satellite diffuse peaks along the [100] axis have been reported for these alloys in the previous papers as an enhanced screening effect of impurities due to the special shapes of the Fermi surfaces of Pt. A question is raised on the Fermi surface effects in Pt and Pt alloys.©2011 The Physical Society of Japan

Two-Dimensional Superconducting Properties of the Organic Superconductor κ_{L}-(DMEDO-TSeF)_{2}[Au(CN)_{4}](THF) with Domain Structures

Tadashi Kawamoto, Takehiko Mori, Takashi Shirahata, and Tatsuro Imakubo — 2011-05-10T09:00:00+09:00

Authors: Tadashi Kawamoto, Takehiko Mori, Takashi Shirahata, and Tatsuro Imakubo
The anisotropy of superconducting coherence lengths of the layered organic superconductor κ_{L}-(DMEDO-TSeF)_{2}[Au(CN)_{4}](THF) with domain structures has been investigated, where DMEDO-TSeF is dimethyl(ethylenedioxy)tetraselenafulvalene and THF is tetrahydrofuran. The field angle dependence of the upper critical field and the short interlayer coherence length indicate that the present compound is a two-dimensional superconductor. Although this compound has domain walls parallel to the conducting layer depending on the orientation of the THF molecules, the interlayer coherence length shorter than the structural correlation length shows that the domain walls parallel to the conducting layers do not affect the superconductivity.©2011 The Physical Society of Japan

Edge States in the Three-Quarter Filled System, α-(BEDT-TTF)_{2}I_{3}

Yasumasa Hasegawa and Keita Kishigi — 2011-05-10T09:00:00+09:00

Authors: Yasumasa Hasegawa and Keita Kishigi
We study the edge states in the two-dimensional conductor α-(BEDT-TTF)_{2}I_{3} theoretically. We show that the Dirac points and the edge states appear at the 3/4 and 1/4 filling as well as the half filling, due to four sites in the unit cell. This situation is in contract with the graphene, where the Dirac points and the edge states appear only at the half filling case. The edge states exist in both vertical and horizontal edges. For the 3/4 filled case it is shown that there exists edge states for all possible edges in the regions of |k_{y}|>|K_{y}| or |k_{y}|<|K_{y}| for the vertical edges, and |k_{x}|>|K_{x}| or |k_{x}|<|K_{x}| for the horizontal edges, where ±(K_{x},K_{y}) are the positions of the Dirac points in the bulk system, depending on the choice of edges.©2011 The Physical Society of Japan

Effects of ppm-Level Imperfection on the Transport Properties of FeSb_{2} Single Crystals

Hidefumi Takahashi, Yukio Yasui, Ichiro Terasaki, and Masatoshi Sato — 2011-05-10T09:00:00+09:00

Authors: Hidefumi Takahashi, Yukio Yasui, Ichiro Terasaki, and Masatoshi Sato
The magnetic susceptibilities, electrical resistivities, Hall coefficients, and Seebeck coefficients have been measured for single crystals of a narrow-gap semiconductor of FeSb_{2} prepared using Sb metals of different purities. Below 40 K, carriers supplied from impurities of the Sb metal used as the raw material determine the transport quantities, making them very sensitive even to a ppm-level impurity concentration. The Seebeck coefficients observed here is as large as ∼-1400 µV/K at 20 K for crystals prepared using Sb of 99.9999% purity. We have not observed, however, the colossal value of ∼-45 mV/K reported by other group, even for the samples having almost equal impurity concentrations to those used in their work. Only the concentration dependence of S has been found to be similar to that of the previous data.©2011 The Physical Society of Japan

Delocalized Positronium in BaF_{2}

Koji Inoue, Naoki Suzuki, Toshio Hyodo, Yasuyoshi Nagai, and Masayuki Hasegawa — 2011-05-10T09:00:00+09:00

Authors: Koji Inoue, Naoki Suzuki, Toshio Hyodo, Yasuyoshi Nagai, and Masayuki Hasegawa
The momentum distribution of positronium (Ps) in BaF_{2} single crystal has been investigated in a temperature range from 10 to 297 K. The existence of the delocalized and localized Ps has been confirmed. The momentum distribution of the delocalized Ps, a central peak at zero momentum and satellite peaks at the momenta corresponding to the reciprocal lattice vectors, has a large width even at 10 K. The width is almost independent of temperature. The behavior is different from that of the delocalized Ps in other ionic crystals. This indicates that the delocalized Ps in BaF_{2} is strongly coupled to the phonon field.©2011 The Physical Society of Japan

Electronic States and Local Density of States in Graphene with a Corner Edge Structure

Yuji Shimomura, Yositake Takane, and Katsunori Wakabayashi — 2011-05-10T09:00:00+09:00

Authors: Yuji Shimomura, Yositake Takane, and Katsunori Wakabayashi
We study electronic states of semi-infinite graphene with a corner edge, focusing on the stability of edge localized states at zero energy. The 60, 90, 120, and 150° corner edges are examined. The 60 and 120° corner edges consist of two zigzag edges, while 90 and 150° corner edges consist of one zigzag edge and one armchair edge. We numerically obtain the local density of states (LDOS) on the basis of a nearest-neighbor tight-binding model by using Haydock's recursion method. We show that edge localized states appear along a zigzag edge of each corner edge structure except for the 120° case. To provide insight into this behavior, we analyze electronic states at zero energy within the framework of an effective mass equation. The result of this analysis is consistent with the behavior of the LDOS.©2011 The Physical Society of Japan

Origin of Retroreflection from a Wing of the Morpho Butterfly

Makoto Kambe, Dong Zhu, and Shuichi Kinoshita — 2011-05-10T09:00:00+09:00

Authors: Makoto Kambe, Dong Zhu, and Shuichi Kinoshita
We have performed detailed angular and spectroscopic measurements on a typical species of Morpho butterflies, Morpho rhetenor, and have found that the butterfly wing shows characteristic retroreflection in a blue region, when light is incident around 10–30° inclined from the normal to the scales on the wing. Various angular and spectroscopic measurements such as detector and sample rotations, and θ–2θ scan are tested, and apart from an inclusive method of θ–φ scan, the sample rotation method is found to be the most appropriate to characterize its optical properties. In order to investigate the origin of the retroreflection, non-standard finite-difference time-domain method is applied and alternate shelf structure is found to be responsible for it. Its optical characteristics are more intuitively understood by two simple models, destructive interference between two units of one-sided shelf structure and two inversely inclined multilayers, although such models are not complete in a strict sense. The presence of retroreflection in this type of animal will be extremely beneficial to show their colors clearly without specular reflection that has no color selectivity.©2011 The Physical Society of Japan

Estimation of the Shortest Average Distance in Bipartite Networks with Given Density

Yilun Shang — 2011-05-10T09:00:00+09:00

Authors: Yilun Shang

Superconductivity in the Honeycomb-Lattice Pnictide SrPtAs

Yoshihiro Nishikubo, Kazutaka Kudo, and Minoru Nohara — 2011-05-10T09:00:00+09:00

Authors: Yoshihiro Nishikubo, Kazutaka Kudo, and Minoru Nohara

Erratum: “Quantum Master Equations for Composite Systems: Is Born–Markov Approximation Really Valid?”

Masatoshi Nakatani and Tetsuo Ogawa — 2011-05-10T09:00:00+09:00

Authors: Masatoshi Nakatani and Tetsuo Ogawa

Interplay of Superconductivity, Antiferromagnetism, and Pauli Depairing in CeCoIn_{5}

Carley Paulsen, Dai Aoki, Georg Knebel, and Jacques Flouquet — 2011-04-25T09:00:00+09:00

Authors: Carley Paulsen, Dai Aoki, Georg Knebel, and Jacques Flouquet
Low temperature magnetization M measurements down to 70 mK have been performed through the superconducting upper critical field H_{c2} of CeCoIn_{5} with the field H parallel to the c-axis of the tetragonal crystal. The crossing through the upper critical field H_{c2}(0) is marked by a sign change in the temperature dependence of M(T). A Fermi liquid law of the magnetization is observed in the superconducting phase while in the paramagnetic state above H_{c2} a quasi-linear temperature dependence is obeyed. The specific heat below H_{c2} is therefor dominated by the increase of γ(H), the linear term of the specific heat, and is marked by a singularity at H_{c2}(0). No indication of the so called Q-phase was observed below H_{c2} (in contrast to the case with H applied in the basal plane).©2011 The Physical Society of Japan

Pressure Evolution of the Magnetic Field induced Ferromagnetic Fluctuation through the Pseudo-Metamagnetism of CeRu_{2}Si_{2}

2011-04-25T09:00:00+09:00

Authors: Dai Aoki, Carley Paulsen, Tatsuma D. Matsuda, Liam Malone, Georg Knebel, Pierre Haen, Pascal Lejay, Rikio Settai, Yoshichika Ōnuki, and Jacques Flouquet
Resistivity measurements performed under pressure in the paramagnetic ground state of CeRu_{2}Si_{2} are reported. They demonstrate that the relative change of effective mass through the pseudo metamagnetic transition is invariant under pressure. The results are compared with the first order metamagnetic transition due to the antiferromagnetism of Ce_{0.9}La_{0.1}Ru_{2}Si_{2} which corresponds to the “negative” pressure of CeRu_{2}Si_{2} by volume expansion. Finally, we describe the link between the spin-depairing of quasiparticles on CeRu_{2}Si_{2} and that of Cooper pairs on the unconventional heavy fermion superconductor CeCoIn_{5}.©2011 The Physical Society of Japan

Disorder-Induced Multiple Transition Involving Z_{2} Topological Insulator

Ai Yamakage, Kentaro Nomura, Ken-Ichiro Imura, and Yoshio Kuramoto — 2011-04-25T09:00:00+09:00

Authors: Ai Yamakage, Kentaro Nomura, Ken-Ichiro Imura, and Yoshio Kuramoto
Effects of disorder on two-dimensional Z_{2} topological insulator are studied numerically by the transfer matrix method. Based on the scaling analysis, the phase diagram is derived for a model of HgTe quantum well as a function of disorder strength and magnitude of the energy gap. In the presence of s_{z} non-conserving spin–orbit coupling, a finite metallic region is found that partitions the two topologically distinct insulating phases. As disorder increases, a narrow-gap topologically trivial insulator undergoes a series of transitions; first to metal, second to topological insulator, third to metal, and finally back to trivial insulator. We show that this multiple transition is a consequence of two disorder effects; renormalization of the band gap, and Anderson localization. The metallic region found in the scaling analysis corresponds roughly to the region of finite density of states at the Fermi level evaluated in the self-consistent Born approximation.©2011 The Physical Society of Japan

Critical and Glassy Phases in Non-Disordered Antiferromagnetic Heisenberg Model on Triangular Lattice

Yusuke Tomita and Naoki Kawashima — 2011-04-25T09:00:00+09:00

Authors: Yusuke Tomita and Naoki Kawashima
We propose a non-disordered antiferromagnetic Heisenberg spin model on a triangular lattice, which exhibits a critical state and a glassy state at low temperatures. The system has three phases, the paramagnetic, the intermediate critical, and the glassy phase. The intermediate phase is characterized by a quasi-long-range order, whereas only short-range order exists in the glassy phase. Using Monte Carlo simulation, the phase transitions and properties of the two phases at low temperatures are examined. Our spin model shows that the variable-length spin and the competition between bilinear and biquadratic interactions are essential for forming the critical and glassy phases.©2011 The Physical Society of Japan

Geometric Quantum Gates, Composite Pulses, and Trotter–Suzuki Formulas

Yasushi Kondo and Masamitsu Bando — 2011-04-25T09:00:00+09:00

Authors: Yasushi Kondo and Masamitsu Bando
We show that all geometric quantum gates (GQG's in short), which are quantum gates only with geometric phases, are robust against control field strength errors. As examples of this observation, we show (1) how robust composite rf-pulses in NMR are geometrically constructed and (2) a composite rf-pulse based on Trotter–Suzuki Formulas is a GQG.©2011 The Physical Society of Japan

Construction of an Isotropic Cellular Automaton for a Reaction–Diffusion Equation by Means of a Random Walk

Akinobu Nishiyama and Tetsuji Tokihiro — 2011-04-25T09:00:00+09:00

Authors: Akinobu Nishiyama and Tetsuji Tokihiro
We propose a new method to construct an isotropic cellular automaton corresponding to a reaction–diffusion equation. The method consists of replacing the diffusion term and the reaction term of the reaction–diffusion equation with random walk of microscopic particles and a discrete vector field which defines time evolution of the particles. The obtained cellular automaton can retain isotropy and therefore reproduces the patterns found in the numerical solutions of the reaction–diffusion equation. As a specific example, we apply the method to the Belousov–Zhabotinsky reaction in excitable media.©2011 The Physical Society of Japan

The Sound Attenuation for the Spin-1 Ising Model on the Bethe Lattice

Erhan Albayrak and Tunc Cengiz — 2011-04-25T09:00:00+09:00

Authors: Erhan Albayrak and Tunc Cengiz
The temperature (T), frequency (w), Onsager coefficient (γ) and external magnetic field (H) dependencies of the sound attenuation near the phase transition temperature (T_{c}) is studied for the spin-1 Ising model on the Bethe lattice for given coordination numbers q in terms of the recursion relations by using Onsager theory of irreversible thermodynamics. It was assumed that the sound wave couples to the order-parameter fluctuations which decay mainly via the order-parameter relaxation process. Two relaxation times are obtained and which are used to find an expression for the sound attenuation coefficient (α). It was found that α presents only one peak for all frequencies when q=6, and two peaks for q=3 and 4 at low frequencies. In addition, α increases with the increasing values of frequency and with the decreasing values of external magnetic field.©2011 The Physical Society of Japan

Rattling Vibrations Observed by Means of Single-Crystal X-ray Diffraction in the Filled Skutterudite ROs_{4}Sb_{12} (R = La, Ce, Pr, Nd, Sm)

Jun-ichi Yamaura and Zenji Hiroi — 2011-04-25T09:00:00+09:00

Authors: Jun-ichi Yamaura and Zenji Hiroi
We prepared a series of high-quality single crystals of the filled skutterudite ROs_{4}Sb_{12} (R = La, Ce, Pr, Nd, Sm) and performed precise X-ray structural analyses to investigate the relation between the crystal structure and rattling vibration of the guest R atoms. The results revealed that in a cage made of Sb, with increasing guest free space from La to Sm, the thermal displacement parameter of the R ion increases and the Einstein temperature, which represents the characteristic energy of the rattling, decreases. Anisotropic distribution of the electron density was observed, in particular for small R ions, which indicates that there is large anharmonicity along the [111] direction that reflects the specific shape of the Sb cage.©2011 The Physical Society of Japan

Magnon Pumping by a Time-Dependent Transverse Magnetic Field in Ferromagnetic Insulators

Kouki Nakata and Gen Tatara — 2011-04-25T09:00:00+09:00

Authors: Kouki Nakata and Gen Tatara
The magnon pumping effect in ferromagnetic insulators under an external time-dependent transverse magnetic field is theoretically studied. Generation of a magnon current is discussed by calculating the magnon source term in the spin continuity equation. This term represents the non-conservation of magnons arising from an applied transverse magnetic field. The magnon source term has a resonance structure as a function of the angular frequency of the transverse field, and this fact is useful to enhance the pumping effect.©2011 The Physical Society of Japan

Tunability of Excited-State Energy Levels of Four-Josephson-Junction Circuit in Crossover from Double-Well to Single-Well Potential

Yoshihiro Shimazu — 2011-04-25T09:00:00+09:00

Authors: Yoshihiro Shimazu
A double-loop four-Josephson-junction (4-JJ) flux qubit is a tunable qubit wherein the potential profile can be varied in situ via two applied magnetic fluxes. This provides a high level of control over state transitions. Here, we report the results of spectroscopic measurements on this system. We observed microwave resonances associated with the first and second excited states. A branch of resonances that is most likely attributable to the third excited state was also observed. The excitation energy spectra for these levels were in qualitative agreement with the results of simplified calculations performed using an effective Hamiltonian with two phases. The three lowest levels characterized in this study may allow novel applications, including those proposed theoretically in the past. Our analysis showed that the potential exhibited a crossover from the commonly used double-well regime to the novel single-well regime. This indicates the possibility of manipulation and readout of a 3-JJ (and 4-JJ) qubit in the single-well regime using a simple technique.©2011 The Physical Society of Japan

On the Puzzle of Odd-Frequency Superconductivity

Hiroaki Kusunose, Yuki Fuseya, and Kazumasa Miyake — 2011-04-25T09:00:00+09:00

Authors: Hiroaki Kusunose, Yuki Fuseya, and Kazumasa Miyake
Since the first theoretical proposal by Berezinskii, an odd-frequency superconductivity has encountered the fundamental problems on its thermodynamic stability and rigidity of a homogenous state accompanied by unphysical Meissner effect. Recently, Solenov et al. [Phys. Rev. B 79 (2009) 132502] have asserted that the path-integral formulation gets rid of the difficulties leading to a stable homogenous phase with an ordinary Meissner effect. Here, we show that it is crucial to choose the appropriate saddle-point solution that minimizes the effective free energy, which was assumed implicitly in the work by Solenov and co-workers. We exhibit the path-integral framework for the odd-frequency superconductivity with general type of pairings, including an argument on the retarded functions via the analytic continuation to the real axis.©2011 The Physical Society of Japan

Eight-Pseudospin Model of KH_{2}PO_{4}-Type Crystals: II. Phase Transitions and Dielectric Susceptibilities

Yoshihiro Ishibashi, Makoto Iwata, and Robert Blinc — 2011-04-25T09:00:00+09:00

Authors: Yoshihiro Ishibashi, Makoto Iwata, and Robert Blinc
The phase transitions in ferroelectric KH_{2}PO_{4} (KDP) and antiferroelectric NH_{4}H_{2}PO_{4} (ADP) crystals are discussed on the basis of the eight-pseudospin model of KH_{2}PO_{4}-type crystals previously proposed, where eight pseudospins represent protons on hydrogen bonds connecting PO_{4} radicals in a unit cell. The dielectric susceptibilities along the c-axis, which is the unique ferroelectric axis, and a (b)-axis, which is perpendicular to the unique axis, are calculated.©2011 The Physical Society of Japan

f-Electron-Nuclear Hyperfine-Coupled Multiplets in the Unconventional Charge Order Phase of Filled Skutterudite PrRu_{4}P_{12}

2011-04-25T09:00:00+09:00

Authors: Yuji Aoki, Takahiro Namiki, Shanta R. Saha, Takashi Tayama, Toshiro Sakakibara, Ryousuke Shiina, Hiroyuki Shiba, Hitoshi Sugawara, and Hideyuki Sato
The filled skutterudite PrRu_{4}P_{12} is known to undergo an unconventional charge order phase transition at 63 K, below which two sublattices with distinct f-electron crystalline-electric-field ground states are formed. In this paper, we study experimentally and theoretically the properties of the charge order phase at very low temperature, particularly focusing on the nature of the degenerate triplet ground state on one of the sublattices. First, we present experimental results of specific heat and magnetization measured with high quality single crystals. In spite of the absence of any symmetry breaking, the specific heat shows a peak structure at T_{p}=0.30 K in zero field; it shifts to higher temperatures as the magnetic field is applied. In addition, the magnetization curve has a remarkable rounding below 1 T. Then, we study the origin of these experimental findings by considering the hyperfine interaction between 4f electron and nuclear spin. We demonstrate that the puzzling behaviors at low temperatures can be well accounted for by the formation of 4f-electron-nuclear hyperfine-coupled multiplets, the first thermodynamical observation of its kind.©2011 The Physical Society of Japan

On the Meissner Effect of the Odd-Frequency Superconductivity with Critical Spin Fluctuations: Possibility of Zero Field FFLO Pairing

Yuki Fuseya and Kazumasa Miyake — 2011-04-25T09:00:00+09:00

Authors: Yuki Fuseya and Kazumasa Miyake
We investigate the influence of critical spin fluctuations on electromagnetic responses in the odd-frequency superconductivity. It is shown that the Meissner kernel of the odd-frequency superconductivity is strongly reduced by the critical spin fluctuation or the massless spin wave mode in the antiferromagnetic phase. These results imply that the superfluid density is reduced, and the London penetration depth is lengthened for the odd-frequency pairing. It is also shown that the zero field Flude–Ferrell–Larkin–Ovchinnikov pairing is spontaneously realized both for even- and odd-frequency in the case of sufficiently strong coupling with low lying spin-modes.©2011 The Physical Society of Japan

Comment on “Orbital Order, Structural Transition and Superconductivity in Iron Pnictides”

Hiroshi Kontani and Seiichiro Onari — 2011-04-25T09:00:00+09:00

Authors: Hiroshi Kontani and Seiichiro Onari

Recent articles in J. Phys. Soc. Jpn.

Spin-Driven Ferroelectricity and Magneto-Electric Effects in Frustrated Magnetic Systems

Numerical-Diagonalization Study of Spin Gap Issue of the Kagome Lattice Heisenberg Antiferromagnet

Linear and Non-Linear Dielectric Responses of a Model Glass Former

Self-Interaction Corrected Electronic Structure and Energy Gap of CuAlO_{2} beyond Local Density Approximation

Traces of Z_{2}-Vortices in CuCrO_{2}, AgCrO_{2}, and PdCrO_{2}

A Question on the Kohn Anomaly and Screening Effects in Pt and Pt Alloys

Two-Dimensional Superconducting Properties of the Organic Superconductor κ_{L}-(DMEDO-TSeF)_{2}[Au(CN)_{4}](THF) with Domain Structures

Edge States in the Three-Quarter Filled System, α-(BEDT-TTF)_{2}I_{3}

Effects of ppm-Level Imperfection on the Transport Properties of FeSb_{2} Single Crystals

Delocalized Positronium in BaF_{2}

Electronic States and Local Density of States in Graphene with a Corner Edge Structure

Origin of Retroreflection from a Wing of the Morpho Butterfly

Estimation of the Shortest Average Distance in Bipartite Networks with Given Density

Superconductivity in the Honeycomb-Lattice Pnictide SrPtAs

Erratum: “Quantum Master Equations for Composite Systems: Is Born–Markov Approximation Really Valid?”

Interplay of Superconductivity, Antiferromagnetism, and Pauli Depairing in CeCoIn_{5}

Pressure Evolution of the Magnetic Field induced Ferromagnetic Fluctuation through the Pseudo-Metamagnetism of CeRu_{2}Si_{2}

Disorder-Induced Multiple Transition Involving Z_{2} Topological Insulator

Critical and Glassy Phases in Non-Disordered Antiferromagnetic Heisenberg Model on Triangular Lattice

Geometric Quantum Gates, Composite Pulses, and Trotter–Suzuki Formulas

Construction of an Isotropic Cellular Automaton for a Reaction–Diffusion Equation by Means of a Random Walk

The Sound Attenuation for the Spin-1 Ising Model on the Bethe Lattice

Rattling Vibrations Observed by Means of Single-Crystal X-ray Diffraction in the Filled Skutterudite ROs_{4}Sb_{12} (R = La, Ce, Pr, Nd, Sm)

Magnon Pumping by a Time-Dependent Transverse Magnetic Field in Ferromagnetic Insulators

Tunability of Excited-State Energy Levels of Four-Josephson-Junction Circuit in Crossover from Double-Well to Single-Well Potential

On the Puzzle of Odd-Frequency Superconductivity

Eight-Pseudospin Model of KH_{2}PO_{4}-Type Crystals: II. Phase Transitions and Dielectric Susceptibilities

f-Electron-Nuclear Hyperfine-Coupled Multiplets in the Unconventional Charge Order Phase of Filled Skutterudite PrRu_{4}P_{12}

On the Meissner Effect of the Odd-Frequency Superconductivity with Critical Spin Fluctuations: Possibility of Zero Field FFLO Pairing

Comment on “Orbital Order, Structural Transition and Superconductivity in Iron Pnictides”