All-electric spin device operation using the Weyl semimetal, WTe$_2$, at room temperature

TL;DR

This paper demonstrates the operation of an all-electric spin device using the Weyl semimetal WTe$_2$ at room temperature, revealing spin polarization due to local symmetry breaking, which could lead to robust spin devices based on topological quantum materials.

Contribution

It reports the first all-electric spin device operation with WTe$_2$ at room temperature, highlighting spin polarization from local symmetry breaking in a Weyl semimetal.

Findings

Spin polarization propagates perpendicular to WTe$_2$ plane.

Systematic experiments exclude artifacts like anomalous Hall effect.

Room-temperature operation of TQM-based spin devices demonstrated.

Abstract

Topological quantum materials (TQMs) possess abundant and attractive spin physics, and a Weyl semimetal is the representative material because of the generation of spin polarization that is available for spin devices due to fictitious Weyl monopoles at the edge of the Weyl node. Meanwhile, a Weyl semimetal allows the other but unexplored spin polarization due to local symmetry breaking. Here, we report all-electric spin device operation using a type-II Weyl semimetal, WTe$_2$, at room temperature. The polarization of spins propagating in the all-electric device is perpendicular to the WTe$_2$ plane, which is ascribed to local in-plane symmetry breaking in WTe$_2$, yielding the spin polarization creation of propagating charged carriers, namely, the spin-polarized state creation from the non-polarized state. Systematic control experiments unequivocally negate unexpected artifacts, such as the anomalous Hall effect, the anisotropic magnetoresistance etc. Creation of all-electric spin devices made of TQMs and their operation at room temperature can pave a new pathway for novel spin devices made of TQMs resilient to thermal fluctuation.