Observation of Spin Hall Effect in Weyl Semimetal WTe2 at Room Temperature

TL;DR

This paper reports the first direct observation of large spin Hall and inverse spin Hall effects in Weyl semimetal WTe2 at room temperature, demonstrating efficient charge-to-spin conversion for spintronic applications.

Contribution

It provides experimental evidence of spin Hall effects in WTe2 at room temperature and combines it with ab initio calculations to show high charge-spin conversion efficiency.

Findings

Large spin Hall effect observed in WTe2 at room temperature

Detection of pure spin current via van der Waals heterostructures with graphene

Supports potential for spintronic device applications

Abstract

Discovery of topological Weyl semimetals has revealed the opportunities to realize several extraordinary physical phenomena in condensed matter physics. Specifically, these semimetals with strong spin-orbit coupling, broken inversion symmetry and novel spin texture are predicted to exhibit a large spin Hall effect that can efficiently convert the charge current to a spin current. Here we report the direct experimental observation of a large spin Hall and inverse spin Hall effects in Weyl semimetal WTe2 at room temperature obeying Onsager reciprocity relation. We demonstrate the detection of the pure spin current generated by spin Hall phenomenon in WTe2 by making van der Waals heterostructures with graphene, taking advantage of its long spin coherence length and spin transmission at the heterostructure interface. These experimental findings well supported by ab initio calculations show a large charge-spin conversion efficiency in WTe2; which can pave the way for utilization of spin-orbit induced phenomena in spintronic memory and logic circuit architectures.