354 citations · 1.8k across the 26 of their papers we have counts for
25 papers
Two-dimensional superconducting diode effect in topological insulator/superconductor heterostructure
Soma Nagahama, Yuki Sato, Minoru Kawamura +7
The superconducting diode effect (SDE) is characterized by the nonreciprocity of Cooper-pair motion with respect to current direction. In three-dimensional (3D) materials, SDE resu…
Quantum geometry in low-energy linear and nonlinear optical responses of magnetic Rashba semiconductor (Ge,Mn)Te
Tsubasa Takagi, Hikaru Watanabe, Ryutaro Yoshimi +7
Quantum geometry appears as a key factor in understanding the optical properties of quantum materials, with the anticipation on diverging or quantized responses near the Dirac and…
Control of nonreciprocal charge transport in topological insulator/superconductor heterostructures with Fermi level tuning and superconducting-layer thickness
Soma Nagahama, Yuki Sato, Minoru Kawamura +7
Nonreciprocal charge transport (NCT) is defined as a phenomenon where electrical resistance depends on the current direction. It has been drawing much attention because it sensitiv…
AC Current-Driven Magnetization Switching and Nonlinear Hall Rectification in a Magnetic Topological Insulator
Yuto Kiyonaga, Masataka Mogi, Ryutaro Yoshimi +7
Spin-orbit torque arising from the spin-orbit-coupled surface states of topological insulators enables current-induced control of magnetization with high efficiency. Here, alternat…
Non-Fermi liquid transport and strong mass enhancement near the nematic quantum critical point in FeSeTe thin films
Yuki Sato, Soma Nagahama, Ilya Belopolski +10
Unconventional superconductivity is often accompanied by non-Fermi liquid (NFL) behavior, which emerges near a quantum critical point (QCP) - a point where an electronic ordered ph…
Charge sensing of few-electron ZnO double quantum dots probed by radio-frequency reflectometry
Kosuke Noro, Motoya Shinozaki, Yusuke Kozuka +6
Zinc oxide (ZnO) has garnered much attention as a promising material for quantum devices due to its unique characteristics. To utilize the potential of ZnO for quantum devices, the…
Emergence of ferroelectric topological insulator as verified by quantum Hall effect of surface states in (Sn,Pb,In)Te films
Ryutaro Yoshimi, Ryosuke Kurihara, Yoshihiro Okamura +9
Emergent phenomena arising from nontrivial band structures based on topology and symmetry have been attracting keen interest in contemporary condensed-matter physics. Materials suc…
This took us a Weyl: synthesis of a semimetallic Weyl ferromagnet with point Fermi surface
Ilya Belopolski, Ryota Watanabe, Yuki Sato +19
Quantum materials governed by emergent topological fermions have become a cornerstone of physics. Dirac fermions in graphene form the basis for moiré quantum matter, and Dirac ferm…
Molecular beam epitaxy of superconducting FeSeTe thin films interfaced with magnetic topological insulators
Yuki Sato, Soma Nagahama, Ilya Belopolski +7
Engineering heterostructures with various types of quantum materials can provide an intriguing playground for studying exotic physics induced by the proximity effect. Here, we repo…
Gate-electric-field and magnetic-field control of versatile topological phases in a semi-magnetic topological insulator
Ryota Watanabe, Ryutaro Yoshimi, Kei S. Takahashi +4
Surface states of a topological insulator demonstrate interesting quantum phenomena, such as the quantum anomalous Hall (QAH) effect and the quantum magnetoelectric effect. Fermi e…
Microwave response of interacting oxide two-dimensional electron systems
D. Tabrea, I. A. Dmitriev, S. I. Dorozhkin +7
We present an experimental study on microwave illuminated high mobility MgZnO/ZnO based two-dimensional electron systems with different electron densities and, hence, varying Coulo…
Molecular beam epitaxy growth of superconducting Sr2RuO4 films
M. Uchida, M. Ide, H. Watanabe +3
We report growth of superconducting Sr2RuO4 films by oxide molecular beam epitaxy (MBE). Careful tuning of the Ru flux with an electron beam evaporator enables us to optimize growt…
Nonlinear response of a MgZnO/ZnO heterostructure close to zero bias
Q. Shi, M. A. Zudov, J. Falson +4
We report on magnetotransport properties of a MgZnO/ZnO heterostructure subjected to weak direct currents. We find that in the regime of overlapping Landau levels, the differential…
Quantized chiral edge conduction on reconfigurable domain walls of a magnetic topological insulator
K. Yasuda, M. Mogi, R. Yoshimi +5
The electronic orders in magnetic and dielectric materials form the domains with different signs of order parameters. The control of configuration and motion of the domain walls (D…
Large Unidirectional Magnetoresistance in a Magnetic Topological Insulator
K. Yasuda, A. Tsukazaki, R. Yoshimi +3
We report current-direction dependent or unidirectional magnetoresistance (UMR) in magnetic/nonmagnetic topological insulator (TI) heterostructures, Cr(BiSb)$_{2-x}…
Enhanced photogalvanic current in topological insulators via Fermi energy tuning
K. N. Okada, N. Ogawa, R. Yoshimi +4
We achieve the enhancement of circular photogalvanic effect arising from the photo-injection of spins in topological insulator thin films by tuning the Fermi level (). A…
Magnetic modulation doping in topological insulators toward higher-temperature quantum anomalous Hall effect
M. Mogi, R. Yoshimi, A. Tsukazaki +5
Quantum anomalous Hall effect (QAHE), which generates dissipation-less edge current without external magnetic field, is observed in magnetic-ion doped topological insulators (TIs),…
Quantum Hall States Stabilized in Semi-magnetic Bilayers of Topological Insulators
R. Yoshimi, K. Yasuda, A. Tsukazaki +4
By breaking the time-reversal-symmetry in three-dimensional topological insulators with introduction of spontaneous magnetization or application of magnetic field, the surface stat…
Nonreciprocal spin wave propagation in chiral-lattice ferromagnets
S. Seki, Y. Okamura, K. Kondou +8
Spin current, i.e. the flow of spin angular momentum or magnetic moment, has recently attracted much attention as the promising alternative for charge current with better energy ef…
Phase-change memory function of correlated electrons in organic conductors
H. Oike, F. Kagawa, N. Ogawa +4
Phase-change memory (PCM), a promising candidate for next-generation non-volatile memories, exploits quenched glassy and thermodynamically stable crystalline states as reversibly s…
Polarization dependent Landau level crossing in a two-dimensional electron system in MgZnO/ZnO-heterostructure
D. Maryenko, J. Falson, Y. Kozuka +2
We report electrical transport measurements in a tilted magnetic field on a high-mobility two-dimensional electron system confined at the MgZnO/ZnO heterointerface. The observation…
Robust formation of skyrmions and topological Hall effect in epitaxial thin films of MnSi
Yufan Li, N. Kanazawa, X. Z. Yu +6
Magneto-transport properties have been investigated for epitaxial thin films of B20-type MnSi grown on Si(111) substrates. Both Lorentz transmission electron microscopy (TEM) image…
Ultrafast Time-Resolved Faraday Rotation in EuO Thin Films
F. Liu, T. Makino, T. Yamazaki +5
We have investigated the ultrafast spin dynamics in EuO thin films by time-resolved Faraday rotation spectroscopy. The photoinduced magnetization is found to be increased in a tran…
Temperature dependent magnetotransport around = 1/2 in ZnO heterostructures
Denis Maryenko, Joseph Falson, Yusuke Kozuka +4
The sequence of prominent fractional quantum Hall states up to =5/11 around =1/2 in a high mobility two-dimensional electron system confined at oxide heterointerface (ZnO) is…