Direct observation of distinct bulk and edge nonequilibrium spin accumulation in ultrathin MoTe2

Abstract Low-symmetry two-dimensional (2D) topological materials such as MoTe2 host efficient charge-to-spin conversion (CSC) mechanisms that can be harnessed for novel electronic and spintronic devices. However, the nature of the various CSC mechanisms and their correlation with underlying crystal...

Full description

Saved in:
Bibliographic Details
Main Authors: Fangchu Chen, Kamal Das, Bowen Yang, Chuangtang Wang, Shazhou Zhong, Diana Golovanova, He Ren, Tianyang Wang, Xuan Luo, Yuping Sun, Liuyan Zhao, Guo-Xing Miao, Binghai Yan, Adam W. Tsen
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-61550-2
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Low-symmetry two-dimensional (2D) topological materials such as MoTe2 host efficient charge-to-spin conversion (CSC) mechanisms that can be harnessed for novel electronic and spintronic devices. However, the nature of the various CSC mechanisms and their correlation with underlying crystal symmetries remain unsettled. In this work, we use local spin-sensitive electrochemical potential measurements to directly probe the spatially dependent nonequilibrium spin accumulation in MoTe2 flakes down to four atomic layers. We are able to clearly disentangle contributions originating from the spin Hall and Rashba-Edelstein effects and uncover an abundance of unconventional spin polarizations that develop uniquely in the sample bulk and edges with decreasing thickness. Using ab-initio calculations, we construct a unified understanding of all the observed CSC components in relation to the material dimensionality and stacking arrangement. Our findings not only illuminate previous CSC results on MoTe2 but also have important ramifications for future devices that can exploit the local and layer-dependent spin properties of this 2D topological material.
ISSN:2041-1723