Hokkaido University · 물리·천문학
메구미 ヤツシュロ 교수의 연구실은 전자 상호작용의 복합적 상호작용, 특히 전하, 스핀, 오비탈, 서브격자, 결합 등의 자유도 간 상호작용이 초래하는 비정상적인 전자적 질서 상태를 중심으로 연구를 전개합니다. 주요 연구 방향은 다중극자(전기, 자계, 자계 토로이드, 전기 토로이드)의 대칭적 분류와 그에 기반한 비보존적 물리현상, 특히 자기 토로이드 모멘트가 초래하는 비선형 전도성 및 다중극자 순서 상태의 안정성에 대한 이론적 분석입니다. 특히 f-전자 물질인 CeCoSi에서의 NQR/NMR 스펙트럼 분석과 자기상전이 메커니즘을 통해 다중극자 상태의 간섭적 특성과 비대칭 구조의 영향을 규명하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Mutual interplay between the electronic degrees of freedom in solids, such as charge, spin, orbital, sublattice, and bond degrees of freedom, is a source of cross-correlated phenomena with unconventional electronic ordered states. Such degrees of freedom can be described by four types of multipoles (electric, magnetic, magnetic toroidal, and electric toroidal) in a unified way, which enable us to tightly connect the microscopic degrees of freedom with macroscopic physical responses in a transpar
A magnetic toroidal moment is a fundamental electronic degree of freedom in the absence of both spatial inversion and time-reversal symmetries and gives rise to novel multiferroic and transport properties. We elucidate essential model parameters of the nonlinear transport in the space-time $(\mathcal{PT})$ symmetric collinear antiferromagnetic metals accompanying a magnetic toroidal moment. By analyzing the longitudinal and transverse components of the second-order nonlinear conductivity on a tw
We study theoretically NQR and NMR spectra in the presence of odd-parity multipoles originating from staggered antiferromagnetic and antiferroquadrupole orderings. For the $f$-electron metal CeCoSi, which is a candidate hosting odd-parity multipoles, we derive an effective hyperfine field acting on a Co nucleus generated from electronic origin multipole moments of the Ce ion in zero and nonzero magnetic fields. We elucidate that emergent odd-parity multipoles give rise to sublattice-dependent sp
We investigate the stability of the multipolar orderings in $f$-electron material CeCoSi based on a self-consistent mean-field calculation for the effective localized model. This material has two ordered phases in the temperature-pressure phase diagram: the antiferromagnetic phase and the nonmagnetic phase, the latter of which has been suggested to be an antiferroquadrupolar phase. Meanwhile, the origin of the antiferroquadrupolar phase has been unclear, since a quadrupole degree of freedom is p
Mutual interplay between the electronic degrees of freedom in solids, such as charge, spin, orbital, sublattice, and bond degrees of freedom, is a source of cross-correlated phenomena with unconventional electronic ordered states. Such degrees of freedom can be described by four types of multipoles (electric, magnetic, magnetic toroidal, and electric toroidal) in a unified way, which enable us to tightly connect the microscopic degrees of freedom with macroscopic physical responses in a transpar
A magnetic toroidal moment is a fundamental electronic degree of freedom in the absence of both spatial inversion and time-reversal symmetries and gives rise to novel multiferroic and transport properties. We elucidate essential model parameters of the nonlinear transport in the space-time ($\mathcal{PT}$) symmetric collinear antiferromagnetic metals accompanying a magnetic toroidal moment. By analyzing the longitudinal and transverse components of the second-order nonlinear conductivity on a tw
