Magnon modes as a joint effect of surface ferromagnetism and spin-orbit coupling in CoSi chiral topological semimetal

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:540

Article

Esin, V. D.¹  Timonina, A., V¹  Kolesnikov, N. N.¹  Deviatov, E., V¹ 

[1] Russian Acad Sci, Inst Solid State Phys, 2 Acad Ossipyan Str, Chernogolovka 142432, Moscow District, Russia

关键词: Topological semimetals;    Spin-orbit coupling;    Surface ferromagnetism;   

DOI  :  10.1016/j.jmmm.2021.168488

来源: Elsevier

【 摘 要 】

CoSi single crystal is a known realization of a chiral topological semimetal with simultaneously broken mirror and inversion symmetries. In addition to the symmetry-induced spin-orbit coupling, surface ferromagnetism is known in nominally diamagnetic CoSi structures, which appears due to the distorted bonds and ordered vacancies near the surface. We experimentally investigate electron transport through a thin CoSi flake at high current density. Surprisingly, we demonstrate dv/dI (I) curves which are qualitatively similar to ones for ferromagnetic multilayers with characteristic dV/dI magnon peaks and unconventional magnetic field evolution of the peaks' positions. We understand these observations as a result of current-induced spin polarization due to the significant spin-orbit coupling in CoSi. Scattering of non-equilibrium spin-polarized carriers within the surface ferromagnetic layer is responsible for the precessing spin-wave excitations, so the observed magnon modes are the joint effect of surface ferromagnetism and spin-orbit coupling in a CoSi chiral topological semimetal. Thus, thin CoSi flakes behave as magnetic conductors with broken inversion symmetry, which is important for different spintronic phenomena.

【 授权许可】

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