Observation of gigantic spin conversion anisotropy in bismuth

Abstract

Whilst the g-factor can be anisotropic due to the spin-orbit interaction (SOI), its existence in solids cannot be simply asserted from a band structure, which hinders progress on studies from such the viewpoints. The g-factor in bismuth (Bi) is largely anisotropic; especially for holes at T-point, the g-factor perpendicular to the trigonal axis is negligibly small (< 0.112), whereas the g-factor along the trigonal axis is very large (62.7). We clarified in this work that the large g- factor anisotropy gives rise to the gigantic spin conversion anisotropy in Bi from experimental and theoretical approaches. Spin-torque ferromagnetic resonance was applied to estimate the spin conversion efficiency in rhombohedral (110) Bi to be 17%, which is unlike the negligibly small efficiency in Bi(111). Harmonic Hall measurements supports the large spin conversion efficiency in Bi(110). This is the first observation of gigantic spin conversion anisotropy as the clear manifestation of the g-factor anisotropy. Beyond the emblematic case of Bi, our study unveiled the significance of the g-factor anisotropy in condensed-matter physics and can pave a pathway toward establishing novel spin physics under g-factor control.

28 pages, 7 figures

References in corpus (6)

• Dissipationless Quantum Spin Current at Room Temperature
• Direct electronic measurement of the spin Hall effect
• Transport Properties and Diamagnetism of Dirac Electrons in Bismuth
• Giant spin Hall angle in the Heusler alloy Weyl ferromagnet Co${}_2$MnGa
• Anomalous sign inversion of spin-orbit torque in ferromagnetic/nonmagnetic bilayer systems due to self-induced spin-orbit torque
• Intrinsic and Extrinsic Spin Hall Effects of Dirac Electrons

Cited by in corpus (5)

• Intrinsic orbital and spin Hall effect in bismuth semimetal
• Charge to spin conversion in atomically thin bismuth
• Temperature dependence of charge-to-spin conversion in rhombohedral (110) bismuth thin film
• Charge-to-spin conversion in epitaxial and polycrystalline Bi and Bi/Ag layers
• Investigating spin and orbital effects via spin-torque ferromagnetic resonance