Staggered spin Hall conductivity

Published

November 25, 2020

Author(s)

Fei Xue, Paul M. Haney

Abstract

The intrinsic spin Hall effect plays an important role in spintronics applications, such as spin-orbit torque-based memory. The bulk space group symmetry determines the form of the bulk spin current conductivity tensor. This paper considers materials for which the local point group symmetry of individual atoms is lower than the global (bulk) symmetry. This enables a position-dependent spin current response, with additional tensor components allowed relative to the bulk response. We present a general method to compute the position-dependent intrinsic spin Hall conductivity, with similar computational effort relative to computing the bulk spin Hall conductivity. We also present the general symmetry-constrained form of the position- dependent spin current response. We apply this method to 1T'-\ch{WTe2}, which exhibits a spatially uniform conventional spin Hall conductivity tensor component $\sigma^y_{xz}$ and a staggered unconventional component $\sigma^z_{xz}$. The magnitude of these two components, around 100 and 20 $\hbar/2e~(\rm \Ω\cdot cm)^{-1}$, respectively, are comparable to the spin-orbit torque exerted on adjacent ferromagnets in experiments. We then consider orthorhombic \ch{PbTe}, in which both uniform and staggered spin current conductivity are one order of magnitude larger.

Citation

Physical Review B

Volume

102

Issue

19

Pub Type

Journals

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DOI Link

Keywords

spin Hall effect, two-dimensional materials

Citation

Xue, F. and Haney, P. (2020), Staggered spin Hall conductivity, Physical Review B, [online], https://doi.org/10.1103/PhysRevB.102.195146 (Accessed April 26, 2024)