Excitonic effects in shift currents of low dimensional materials from time-dependent GW approach

ORAL

Abstract

We present first-principles studies on shift currents with excitonic effects in 2D materials using an adiabatic time-dependent GW approach. Shift current in a noncentrosymmetric semiconductor is a DC current generated by optical excitations from a nonlinear response processes. Using a newly developed real-time simulation method, we are able to include excitonic effects in the nonlinear responses from first principles, treating the complicated electron-hole interaction at the GW plus Bethe-Salpeter equation level for the first time. We applied this method to study shift currents in monolayer GeS and found strongly enhanced responses due to excitonic effects. Most interestingly, the dominant contributions to the shift currents here are generated at in-gap frequencies, which peaked at energies below the quasi-particle band gap by the exciton binding energies.

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Presenters

  • Yang-hao Chan

    Lawrence Berkeley National Lab, Academia Sinica

Authors

  • Yang-hao Chan

    Lawrence Berkeley National Lab, Academia Sinica

  • Diana Qiu

    Physics, University of California at Berkeley, Physics, University of California, Berkeley, Lawrence Berkeley National Lab and University of California, Berkeley, University of California - Berkeley, Lawrence Berkeley National Laboratory

  • Felipe Da Jornada

    Department of Physics, University of California, Berkeley, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Physics, University of California at Berkeley, Lawrence Berkeley National Laboratory, University of California at Berkeley and Lawrence Berkeley National Laboratory, Physics, University of California, Berkeley, UC Berkeley and Lawrence Berkeley National Lab, Lawrence Berkeley National Lab, Lawrence Berkeley National Lab and University of California, Berkeley

  • Steven G. Louie

    Physics, UC Berkeley, University of California, Berkeley, Department of Physics, University of California, Berkeley, Physics Department, UC Berkeley and Lawrence Berkeley National Lab, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Physics, University of California at Berkeley, University of California at Berkeley and Lawrence Berkeley National Lab, University of California at Berkeley and Lawrence Berkeley National Laboratory, Physics, University of California, Berkeley, UC Berkeley and Lawrence Berkeley National Lab, Physics, University of California - Berkeley, Physics and Materials Sciences, University of California at Berkeley and Lawrence Berkeley National Laboratory, Lawrence Berkeley National Lab and University of California, Berkeley, University of California - Berkeley, Lawrence Berkeley National Laboratory