Light-induced shift current vortex crystals in moiré heterobilayers

ORAL

Abstract

Transition metal dichalcogenide (TMD) moiré superlattices provide an emerging platform to explore various light-induced phenomena. Recently, the discoveries of novel moiré excitons have attracted great interest. The nonlinear optical responses of these systems are however still underexplored. Here, we report investigation of light-induced shift currents in the WSe2/WS2 moiré superlattice. We discover a striking phenomenon of the formation of shift current vortex crystals -- i.e., two-dimensional periodic arrays of moiré-scale current vortices and associated magnetic fields with remarkable intensity under laboratory laser setup. Furthermore, we demonstrate high optical tunability of these current vortices – their location, shape, chirality and magnitude can be tuned by the frequency, polarization and intensity of the incident light. Our findings provide a promising all-optical control route to manipulate nanoscale shift current density distributions and magnetic field patterns, as well as shed light on nonlinear optical responses in moiré quantum matter and their possible applications.

* This work is supported by the U.S. Department of Energy and the National Science Foundation.

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Presenters

  • CHEN HU

    University of California, Berkeley, Lawrence Berkeley National Laboratory

Authors

  • CHEN HU

    University of California, Berkeley, Lawrence Berkeley National Laboratory

  • Mit H Naik

    University of California, Berkeley

  • Yang-hao Chan

    Academia Sinica, Institute of Atomic and Molecular Sciences, Academia Sinica and Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan

  • Jiawei Ruan

    University of California at Berkeley, UC Berkeley, Lawrence Berkeley National Laboratory, University of California at Berkeley, and Lawrence Berkeley National Laboratory

  • Steven G Louie

    University of California at Berkeley, University of California at Berkeley and Lawrence Berkeley National Laboratory, University of California at Berkeley, and Lawrence Berkeley National Laboratory, UC-Berkeley