M. Tanaka 교수

Magnetic Weyl semimetals attract considerable interest not only for their topological quantum phenomena but also as an emerging materials class for realizing quantum anomalous Hall effect in the two-dimensional limit. A shandite compound Co₃Sn₂S₂ with layered kagome-lattices is one such material, where vigorous efforts have been devoted to synthesize the two-dimensional crystal. Here, we report a synthesis of Co₃Sn₂S₂ thin flakes

The intrinsic Hall effect allows for the generation of a nondissipative charge neutral current, such as a pure spin current generated via the spin Hall effect. Breaking of the spatial inversion or time reversal symmetries, or the spin-orbit interaction is generally considered necessary for the generation of such a charge neutral current. Here, we challenge this general concept and present generation and detection of a charge neutral current in a centrosymmetric material with little spin-orbit in

The quantum Hall system can be used to study many-body physics owing to its multiple internal electronic degrees of freedom and tunability. While quantum phase transitions have been studied intensively, research on the temperature-induced phase transitions of this system is limited. We measured the pure bulk conductivity of a quantum Hall antiferromagnetic state in bilayer graphene over a wide range of temperatures and revealed the two-step phase transition associated with the breaking of the lo

The author studies developments in epitaxial ferromagnetic heterostructures based on semiconductors towards spintronics and also presents a magnetotransport study on ferromagnetic III-V semiconductor heterostructures with high Curie temperature T/sub c/.

Unconventional magnetoresistance is a fascinating quantum phenomenon that continues to draw significant interest in condensed-matter physics. ${\mathrm{Mn}}_{3}{\mathrm{Si}}_{2}{\mathrm{Te}}_{6}$ has emerged as such a novel magnetoresistance (MR) material, notable for its largest MR exceeding conventional colossal magnetoresistance materials and pronounced directional anisotropy. Despite extensive research, the mechanisms driving MR in ${\mathrm{Mn}}_{3}{\mathrm{Si}}_{2}{\mathrm{Te}}_{6}$ remain

Summary form only given. This paper reviews the recent developments of epitaxial ferromagnetic heterostructures based on semiconductors for spintronics. The magnetotransport of prepared ferromagnetic III-V semiconductor heterostructures (Mn-delta-doped GaAs/Be-doped AlGaAs) and the control of ferromagnetism in the heterostructures by using gate electric field and light irradiation at relatively high Curie temperature (TC) (/spl sim/100 K) are also studied. This paper proposes and theoretically a

The quantum Hall system can be used to study many-body physics owing to its multiple internal electronic degrees of freedom and tunability. While quantum phase transitions have been studied intensively, research on the temperature-induced phase transitions of this system is limited. We measured the pure bulk conductivity of a quantum Hall antiferromagnetic state in bilayer graphene over a wide range of temperatures and revealed the two-step phase transition associated with the breaking of the lo

The physics of superconductivity in magic-angle twisted bilayer graphene (MATBG) is a topic of keen interest in moiré systems research, and it may provide insight into the pairing mechanism of other strongly correlated materials such as high-$T_{\mathrm{c}}$ superconductors. Here, we use DC-transport and microwave circuit quantum electrodynamics (cQED) to measure directly the superfluid stiffness of superconducting MATBG via its kinetic inductance. We find the superfluid stiffness to be much lar