All-Optical Materials Design of Dissipationless Chiral Edge Modes in Transition-Metal Dichalcogenides

ORAL

Abstract

Spurred by the recent progress in transient melting, enhancement and induction of electronic order, a particularly tantalizing prospect concerns the possibility to instead access dynamical steady states with distinct non-equilibrium phase transitions, to affect electronic transport. Here, we show that the interplay of crystal symmetry and optical pumping of monolayer transition-metal dichalcogenides (TMDCs) provides a novel avenue to engineer topologically-protected chiral edge modes, facilitating optically-switchable conduction channels that are insensitive to disorder. Intriguingly, while TMDCs are canonically described as condensed-matter realizations of massive relativistic fermions, here we predict from first principles that circularly-polarized pumping instead accesses the intrinsic three-band nature near the band edges to selectively photo-induce topological band inversions at low pump intensities, while simultaneously limiting absorption for sub-gap pump frequencies. The results presented provide a new strategy to predict and design topological materials out of equilibrium, and should be readily applicable to other classes of semiconductors.

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Authors

  • Martin Claassen

    Department of Applied Physics, Stanford University

  • Chunjing Jia

    SIMES, SLAC National Accelerator Laboratory and Stanford University, Stanford Institute for Materials and Energy Sciences, SLAC & Stanford University, SIMES SLAC National Accelerator Laboratory, Department of Applied Physics, Stanford University; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator

  • Brian Moritz

    SLAC National Accelerator Laboratory and Stanford University, Stanford Institute for Materials and Energy Sciences, SLAC & Stanford University

  • Tom Devereaux

    SIMES, SLAC National Accelerator Laboratory and Stanford University, Stanford Institute for Materials and Energy Sciences, SLAC & Stanford University, SIMES SLAC National Accelerator Laboratory, Stanford Institute of Materials and Energy Sciences, SLAC, Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, USA, Stanford University