228 citations · 1.7k across the 25 of their papers we have counts for
25 papers
Field-tunable Weyl points and large anomalous Hall effects in degenerate magnetic semiconductor EuMgBi
M. Kondo, M. Ochi, R. Kurihara +10
Magnets, with topologically-nontrivial Dirac/Weyl points, have recently attracted significant attention owing to the unconventional physical properties, such as large anomalous Hal…
Enhancing thermopower and Nernst signal of high-mobility Dirac carriers by Fermi level tuning in the layered magnet EuMnBi
Keigo Tsuruda, Kento Nakagawa, Masayuki Ochi +5
Dirac/Weyl semimetals hosting linearly-dispersing bands have received recent attention for potential thermoelectric applications, since their ultrahigh-mobility carriers could gene…
Tunable spin-valley coupling in layered polar Dirac metals
Masaki Kondo, Masayuki Ochi, Tatsuhiro Kojima +9
In non-centrosymmetric metals, spin-orbit coupling (SOC) induces momentum-dependent spin polarization at the Fermi surfaces. This is exemplified by the valley-contrasting spin pola…
Ta Nuclear quadrupole resonance study of non-centrosymmetric superconductor PbTaSe
K. Yokoi, M. Yashima, H. Murakawa +5
We report on a pure Ta-nuclear quadrupole resonance (NQR) measurement of PbTaSe at zero magnetic field, which has the advantage of directly probing the intrinsic superc…
Bulk quantum Hall effect of spin-valley-coupled Dirac fermions in a polar antiferromagnet BaMnSb
H. Sakai, H. Fujimura, S. Sakuragi +16
Unconventional features of relativistic Dirac/Weyl quasi-particles in topological materials are most evidently manifested in the 2D quantum Hall effect (QHE), whose variety is furt…
Large Enhancement of Thermoelectric Efficiency Due to a Pressure-Induced Lifshitz Transition in SnSe
T. Nishimura, H. Sakai, H. Mori +10
Lifshitz transition, a change in Fermi surface topology, is likely to greatly influence exotic correlated phenomena in solids, such as high-temperature superconductivity and comple…
Limits of Validity of Rashba Model in BiTeI: A High-field Magneto-optical Study
S. Bordacs, M. Orlita, M. Sikula +2
It was recently shown that BiTeI, a semiconductor with polar crystal structure, possesses a giant spin-splitting of electrons, which has been interpreted in terms of Rashba-type sp…
Quantitative evaluation of Dirac physics in PbTe
Kazuto Akiba, Atsushi Miyake, Hideaki Sakai +7
The magnetic field dependence of electronic transport, magnetic, and elastic properties in single crystals of PbTe were investigated in high magnetic fields up to 55 T. The magneto…
Microwave non-reciprocity of magnon excitations in a non-centrosymmetric antiferromagnet BaMnGeO
Y. Iguchi, Y. Nii, M. Kawano +3
We have investigated the microwave non-reciprocity for a non-centrosymmetric antiferromagnet BaMnGeO. The magnon modes expected by the conventional spin wave theory for…
Exfoliation of single layer BiTeI flakes
Bálint Fülöp, Zoltán Tajkov, János Pető +9
Spin orbit interaction can be strongly boosted when a heavy element is embedded into an inversion asymmetric crystal field. A simple structure to realize this concept in a 2D cryst…
Evolution of the 2D antiferromagnetism with temperature and magnetic field in multiferroic BaCoGeO
V. Hutanu, A. P. Sazonov, M. Meven +11
We report on spherical neutron polarimetry and unpolarized neutron diffraction in zero magnetic field as well as flipping ratio and static magnetization measurements in high magnet…
Landau Level Spectroscopy of Dirac Electrons in a Polar Semiconductor with Giant Rashba Spin Splitting
Sándor Bordács, Joseph G. Checkelsky, Hiroshi Murakawa +2
Optical excitations of BiTeI with large Rashba spin splitting have been studied in an external magnetic field () applied parallel to the polar axis. A sequence of transitions be…
Four-coloured Spin-wave Excitations in Multiferroic Materials
Istvan Kezsmarki, David Szaller, Sandor Bordacs +5
The optical magnetoelectric effect, which is an inherent attribute of the spin excitations in multiferroics, drastically changes their optical properties compared to conventional m…
Strongly spin-orbit coupled two-dimensional electron gas emerging near the surface of polar semiconductors
M. Sakano, M. S. Bahramy, A. Katayama +12
We investigate the two-dimensional (2D) highly spin-polarized electron accumulation layers commonly appearing near the surface of n-type polar semiconductors BiTeX (X = I, Br, and…
Giant magneto-optical response in non-magnetic semiconductor BiTeI driven by bulk Rashba spin splitting
L. Demkó, G. A. H. Schober, V. Kocsis +7
We study the magneto-optical (MO) response of polar semiconductor BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being non-magnetic, the material…
Three-dimensional bulk band dispersion in polar BiTeI with giant Rashba-type spin splitting
M. Sakano, J. Miyawaki, A. Chainani +12
In layered polar semiconductor BiTeI, giant Rashba-type spin-split band dispersions show up due to the crystal structure asymmetry and the strong spin-orbit interaction. Here we in…
Spin-stretching modes in anisotropic magnets: spin-wave excitations in the multiferroic Ba2CoGe2O7
K. Penc, J. Romhányi, T. Rõõm +10
We studied spin excitations of the multiferroic Ba2CoGe2O7 in high magnetic fields up to 33 T. In the electron spin resonance and far infrared absorption spectra we found several s…
Mechanisms of enhanced orbital dia- and paramagnetism: Application to the Rashba semiconductor BiTeI
G. A. H. Schober, H. Murakawa, M. S. Bahramy +4
We study the magnetic susceptibility of a layered semiconductor BiTeI with giant Rashba spin splitting both theoretically and experimentally to explore its orbital magnetism. Apart…
Chirality of Matter Shows Up via Spin Excitations
Sandor Bordacs, Istvan Kezsmarki, David Szaller +10
Right- and left-handed circularly polarized light interact differently with electronic charges in chiral materials. This asymmetry generates the natural circular dichroism and gyro…
Magnetic-field induced competition of two multiferroic orders in a triangular-lattice helimagnet MnI2
T. Kurumaji, S. Seki, S. Ishiwata +4
Magnetic and dielectric properties with varying magnitude and direction of magnetic field H have been investigated for a triangular lattice helimagnet MnI2. The in-plane electric p…
Giant directional dichroism of terahertz light in resonance with magnetic excitations of the multiferroic oxide BaCoGeO
I. Kezsmarki, N. Kida, H. Murakawa +3
We propose that concurrently magnetic and ferroelectric, i.e. multiferroic, compounds endowed with electrically-active magnetic excitations (electromagnons) provide a key to produc…
Cupric chloride CuCl2 as an S=1/2 chain multiferroic
S. Seki, T. Kurumaji, S. Ishiwata +6
Magnetoelectric properties were investigated for an S=1/2 chain antiferromagnet CuCl2, which turns out to be the first example of non-chalcogen based spiral-spin induced multiferro…
Ferroelectricity induced by spin-dependent metal-ligand hybridization in BaCoGeO
H. Murakawa, Y. Onose, S. Miyahara +2
We have investigated the variation of induced ferroelectric polarization under magnetic field with various directions and magnitudes in a staggered antiferromagnet BaCoGeO$…
Dynamics of Multiferroic Domain Wall in Spin-Cycloidal Ferroelectric DyMnO
F. Kagawa, M. Mochizuki, Y. Onose +4
We report the dielectric dispersion of the giant magnetocapacitance (GMC) in multiferroic DyMnO over a wide frequency range. The GMC is found to be attributable not to the so…