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Updated: Jul 8, 2025
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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
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Light-induced shift current vortex crystals in moiré heterobilayers
Chen Hu1,2, Mit H Naik1,2, Yang-Hao Chan1,2,3
1Department of Physics, University of California at Berkeley, Berkeley, CA 94720.
Summary
Researchers discovered light-induced shift current vortex crystals in WSe2/WS2 moiré superlattices. These novel structures exhibit tunable properties and are influenced by electron-hole interactions, opening new avenues for optoelectronic applications.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Optoelectronics
Background:
- Transition metal dichalcogenide (TMD) moiré superlattices are a novel platform for studying light-matter interactions.
- Moiré excitons in these systems have garnered significant interest, but their nonlinear optical responses remain largely unexplored.
Purpose of the Study:
- To investigate light-induced shift currents in WSe2/WS2 moiré superlattices.
- To explore the formation and properties of nonlinear optical responses in these engineered quantum materials.
Main Methods:
- Experimental investigation of shift currents using a laboratory laser setup.
- Analysis of the optical tunability of shift current vortex crystals.
- Theoretical consideration of electron-hole interactions (excitonic effects).
Main Results:
- Observation of shift current vortex crystals, forming 2D periodic arrays of current vortices and magnetic fields.
- Demonstration of optical tunability of vortex properties (location, shape, chirality, magnitude) via incident light parameters.
- Identification of the crucial role of excitonic effects in shift current generation and distribution.
Conclusions:
- Shift current vortex crystals represent a striking nonlinear optical phenomenon in TMD moiré superlattices.
- All-optical control of nanoscale current and magnetic field patterns is achievable.
- Findings advance understanding of nonlinear optics in moiré quantum matter and suggest potential applications.
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