79 citations · 418 across the 26 of their papers we have counts for
8 papers · 1 filter
Observation of g-wave altermagnetic multipole
Ryo Misawa, Rikuto Oiwa, Shunsuke Kitou +16
Over the past few years, altermagnets have emerged as a new class of collinear magnets with broken time-reversal symmetry, offering novel opportunities for spintronics beyond conve…
Sixteenfold Classification of Many-Body Multipoles from Rotation-Compatible Canonical Symmetries
Shingo Kuniyoshi, Rikuto Oiwa, Satoru Hayami
The conventional multipole framework provides a standard symmetry-based language for one-body electronic degrees of freedom, but fails to distinguish physically distinct sectors in…
Piezoaxial coupling for strain-selected ferroaxial domain control
Rikuto Oiwa, Satoru Hayami
We formulate a symmetry-based hierarchy of strain-derived conjugate fields for ferroaxial order, and demonstrate strain-selected ferroaxial domain control using first-principles ca…
Circular Raman responses from angular-momentum inequivalence in CoSi
Yuki Suganuma, Gakuto Kusuno, Kohei Miyazaki +8
Circularly polarized Raman scattering in solids exhibits distinct phenomena such as Raman optical activity (ROA) and chiral-phonon-induced frequency splitting, whose relationship h…
Effective phonon models based on symmetry-adapted multipole basis -- Hidden chiral phonon angular momentum splitting in ferroaxial systems
Yu Xie, Rikuto Oiwa, Satoru Hayami
We propose a symmetry-based framework for constructing effective harmonic phonon models using a symmetry-adapted multipole basis. By decomposing the force-constant matrix into bond…
Electric toroidal octupolar symmetry in pyrite FeS probed by Raman optical activity
Yuki Suganuma, Gakuto Kusuno, Hikaru Watanabe +4
We report Raman optical activity in pyrite FeS, which hosts an electric toroidal octupolar symmetry. A clear and reproducible sign reversal of the circular intensity difference…
Theory of Many-Body Multipole Operators in Single-Centered Electron Systems: Two-Body Toroidal Monopoles in Spinless Orbitals
Shingo Kuniyoshi, Rikuto Oiwa, Satoru Hayami
One-body multipole operators are defined as irreducible representations of rotational symmetry together with spatial-inversion and time-reversal symmetries, providing a systematic…
Large magneto-optical Kerr effect induced by collinear antiferromagnetic order
H. Yoshimochi, K. Yoshida, R. Oiwa +6
In modern technology, the optical readout of magnetic information is conventionally achieved by the magneto-optical Kerr effect, i.e., the polarization rotation of reflected light.…