Room-Temperature Manipulation of Spin Texture in a Dirac Semimetal

Abstract

Charge-current-induced spin-polarized current, via spin-momentum-locked states, is very attractive for spintronics. The orientation of spin polarization caused by an electric field depends on the helicity of the spin texture, which is normally opposite for typical topological surface states and Rashba states. Here, we report the manipulation of the two opposite spin textures in Dirac semimetal ${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$ nanoplates. Spin-polarized transport signals originated from topological surface states are detected through Hall-bar-like $\mathrm{Co}$ electrodes, showing a maximum at the Dirac point and robustness up to room temperature. By comparison, opposite helicity of the spin texture is measured by applying $\mathrm{Co}$ electrodes across the whole nanoplate. Furthermore, it is found that the opposite spin texture is only localized underneath the electrodes, and the spin texture of topological surface states can be singled out by a nonlocal device geometry. The results show that the clockwise and counterclockwise spin textures can be achieved simultaneously in a single Dirac semimetal device by patterning metal electrodes with different configurations, which are promising for future spintronic applications.