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Inversion Symmetry Breaking Induced Valley Hall Effect in Multilayer WSe2
Hongming Guan1, Ning Tang1,2,3, Hao Huang4
1State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics , Peking University , Beijing 100871 , P.R. China.
ACS Nano
|July 20, 2019
Summary
Researchers observed the valley Hall effect (VHE) in multilayer tungsten diselenide (WSe2) at room temperature. This demonstrates the potential of WSe2 for future valleytronics applications by controlling the K (K’) valley degree of freedom.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Two-dimensional transition metal dichalcogenides (TMDs) exhibit a K (K') valley degree of freedom (DOF).
- Valleytronics, which utilizes this valley DOF for electronic applications, is an emerging research area.
- Controlling and observing valley-dependent phenomena is crucial for advancing valleytronics.
Purpose of the Study:
- To investigate the possibility of observing the valley Hall effect (VHE) in multilayer tungsten diselenide (WSe2).
- To explore the role of spatial-inversion symmetry breaking in inducing valley polarization.
- To assess the potential of WSe2 as a material for valleytronics.
Main Methods:
- Applying an out-of-plane electric field to break spatial-inversion symmetry in multilayer WSe2.
- Observing and analyzing the resulting charge carrier behavior and spatial polarization.
- Characterizing the emergence of non-zero Berry curvature.
Main Results:
- The valley Hall effect (VHE) was successfully observed in multilayer WSe2 at room temperature.
- An out-of-plane electric field induced spatial-inversion symmetry breaking.
- Carriers at the K (K') valley were deflected to opposite sides, showing spatial polarization.
Conclusions:
- The observation of VHE confirms the generation of the K (K') valley degree of freedom in multilayer WSe2.
- Multilayer WSe2 is a promising candidate material for future valleytronics devices.
- This study opens new avenues for exploring valley-dependent phenomena in 2D materials.
Keywords:
Berry curvaturemultilayer WSespatial-inversion symmetryvalley Hall effectvalley degree of freedomMore Related Videos
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