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arXiv · 2409.08040

Nonlinear charge and thermal transport properties induced by orbital magnetic moment in chiral crystal cobalt monosilicide

Kazuki Nakazawa·Terufumi Yamaguchi·Ai Yamakage
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Abstract

The existence of exotic singularities in momentum space, such as spin-1 excitations and Rarita-Schwinger-Weyl (RSW) fermions, has been discussed so far to explore unique phenomena in the nonmagnetic B20-type compounds. Meanwhile, the Nonlinear Thermo-Electric (NCTE) charge and thermal Hall effect, a response proportional to the cross product of the electric field and temperature gradient, is expected in this chiral material, yet remains unexplored in B20-type compounds. Here, based on $ab \ initio$ calculations and symmetry analysis, we quantitatively analyze the NCTE charge and thermal Hall effects in cobalt monosilicide, obtaining experimentally measurable values of NCTE charge and thermal Hall current along [111] direction, which is not expected for second-order current responses to the DC electric field. Furthermore, we demonstrate that these significant responses are enhanced around RSW fermions and spin-1 excitations. Additionally, we clarify that the NCTE Hall effect is solely governed by orbital magnetic moments due to the cancellation of Berry curvature contributions in cubic chiral crystals.

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Kazuki Nakazawa, Terufumi Yamaguchi, Ai Yamakage. 2024-09-12. Nonlinear charge and thermal transport properties induced by orbital magnetic moment in chiral crystal cobalt monosilicide. https://doi.org/10.1103/physrevb.111.045161

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