paper

Spin-orbit driven spin depolarization in the ferromagnetic Weyl semimetal Co3Sn2S2

arXiv:1906.06557 · doi:10.1103/PhysRevB.102.104434

Abstract

Co $_{3}$ Sn $_{2}$ S $_{2}$ has recently emerged as a ferromagnetic Weyl semi-metal. Theoretical investigation of the spin-split bands predicted half metalicity in the compound. Here, we report the detection of a spin polarized supercurrent through a Nb/Co $_{3}$ Sn $_{2}$ S $_{2}$ point contact where Andreev reflection is seen to be large indicating a large deviation from half metallicity. In fact, analysis of the Andreev reflection spectra reveals only 50\% spin polarization at the Fermi level of Co $_{3}$ Sn $_{2}$ S $_{2}$ . Our theoretical calculations of electronic Density of States (DOS) reveal a spin depolarizing effect near the Fermi energy when the role of spin-orbit coupling is included. Inclusion of spin-orbit coupling also reveals particle-hole asymmetry that explains a large asymmetry observed in our experimental Andreev reflection spectra.

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