Unconventional Charge–Spin Conversion in Weyl-Semimetal WTe2
Artikel i vetenskaplig tidskrift, 2020

An outstanding feature of topological quantum materials is their novel spin topology in the electronic band structures with an expected large charge-to-spin conversion efficiency. Here, a charge-current-induced spin polarization in the type-II Weyl semimetal candidate WTe2 and efficient spin injection and detection in a graphene channel up to room temperature are reported. Contrary to the conventional spin Hall and Rashba–Edelstein effects, the measurements indicate an unconventional charge-to-spin conversion in WTe2, which is primarily forbidden by the crystal symmetry of the system. Such a large spin polarization can be possible in WTe2 due to a reduced crystal symmetry combined with its large spin Berry curvature, spin–orbit interaction with a novel spin-texture of the Fermi states. A robust and practical method is demonstrated for electrical creation and detection of such a spin polarization using both charge-to-spin conversion and its inverse phenomenon and utilized it for efficient spin injection and detection in the graphene channel up to room temperature. These findings open opportunities for utilizing topological Weyl materials as nonmagnetic spin sources in all-electrical van der Waals spintronic circuits and for low-power and high-performance nonvolatile spintronic technologies.

unconventional charge–spin conversion

type-II

graphene

current-induced spin polarization

Edelstein effect

spin-momentum locking

Weyl-semimetals

WTe 2

van der Waals heterostructures

Författare

Zhao Bing

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

University of Science and Technology Beijing

Bogdan Karpiak

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Dmitrii Khokhriakov

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Annika Johansson

Max-Planck-Gesellschaft

Martin-Luther-Universität Halle-Wittenberg

Anamul Md Hoque

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Xiaoguang Xu

University of Science and Technology Beijing

Yong Jiang

University of Science and Technology Beijing

I. Mertig

Max-Planck-Gesellschaft

Martin-Luther-Universität Halle-Wittenberg

Saroj Prasad Dash

Chalmers grafencentrum

Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik

Advanced Materials

09359648 (ISSN) 15214095 (eISSN)

Vol. In Press

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Den kondenserade materiens fysik

DOI

10.1002/adma.202000818

Mer information

Senast uppdaterat

2020-08-28