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Giant spin Hall effect in AB-stacked MoTe2/WSe2 bilayers

Cornell Affiliated Author(s)

Author

Z. Tao
B. Shen
W. Zhao
N.C. Hu
T. Li
S. Jiang
L. Li
K. Watanabe
T. Taniguchi
A.H. MacDonald
J. Shan
K.F. Mak

Abstract

The spin Hall effect (SHE), in which an electrical current generates a transverse spin current, plays an important role in spintronics for the generation and manipulation of spin-polarized electrons. The phenomenon originates from spin–orbit coupling. In general, stronger spin–orbit coupling favours larger SHEs but shorter spin relaxation times and diffusion lengths. However, correlated magnetic materials often do not support large SHEs. Achieving large SHEs, long-range spin transport and magnetism simultaneously in a single material is attractive for spintronics applications but has remained a challenge. Here we demonstrate a giant intrinsic SHE coexisting with ferromagnetism in AB-stacked MoTe2/WSe2 moiré bilayers by direct magneto-optical imaging. Under moderate electrical currents with density <1 A m−1, we observe spin accumulation on transverse sample edges that nearly saturates the spin density. We also demonstrate long-range spin Hall transport and efficient non-local spin accumulation that is limited only by the device size (about 10 µm). The gate dependence shows that the giant SHE occurs only near the interaction-driven Chern insulating state. At low temperatures, it emerges after the quantum anomalous Hall breakdown. Our results demonstrate moiré engineering of Berry curvature and electronic correlation for potential spintronics applications. © 2023, The Author(s), under exclusive licence to Springer Nature Limited.

Date Published

Journal

Nature Nanotechnology

Volume

19

Issue

1

Number of Pages

28-33,

URL

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85168099132&doi=10.1038%2fs41565-023-01492-2&partnerID=40&md5=55302a27e6fef39e0590416bdf446f82

DOI

10.1038/s41565-023-01492-2

Group (Lab)

Jie Shan Group
Kin Fai Mak Group

Funding Source

DMR-1719875
DMR-1807810
DMR-2039380
FA9550-19-1-0390
NNCI-2025233
DE-SC0019481
JPMJCR15F3

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