Open AccessManipulation of valley splitting for the WSe2/NiCl2 heterostructure by adjusting the interlayer spacing and constructing a NiCl2/WSe2/NiCl2 heterojunction
Author(s) -
Sukai Teng,
Xiujuan Mao,
Ze Liu,
Yang Liu,
Xiuting Xu,
Linyang Li,
Xinjian Xie,
Shanshan Fan,
Guoxiang Zhou,
Jun Li,
Jia Li
Publication year - 2020
Publication title -
new journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.584
H-Index - 190
ISSN - 1367-2630
DOI - 10.1088/1367-2630/abc2e6
Subject(s) - heterojunction , berry connection and curvature , physics , condensed matter physics , degenerate energy levels , stacking , curvature , monolayer , ferromagnetism , materials science , nanotechnology , geometric phase , geometry , nuclear magnetic resonance , quantum mechanics , mathematics
The electronic band structure and valley splitting of the WSe 2 /NiCl 2 heterostructure have been investigated by density functional theory and Berry curvature calculations. We demonstrate that the valley polarization of monolayer WSe 2 is induced due to the magnetic proximity effect caused by the single layer of ferromagnetic NiCl 2 . The magnitude of valley splitting depends on the stacking configurations of WSe 2 /NiCl 2 , and the maximum value of valley splitting reaches −11.87 meV. Large valley splitting can be achieved by adjusting the layer spacing and constructing a NiCl 2 /WSe 2 /NiCl 2 heterojunction with Ni spins arranged in parallel between two NiCl 2 sheets. The valley-contrasting Berry curvature between the K and K ′ valleys suggests that the WSe 2 /NiCl 2 -based heterostructure could potentially be used as a valleytronic device to realize the valley-polarized anomalous Hall effect as both spin and valley filter.
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