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First-principles calculations of electron-phonon interactions with GW corrections for localized defect states in monolayer WS<sub>2</sub> with a sulfur vacancy

ORAL

Abstract

Recent scanning tunneling spectroscopy measurements on a sulfur vacancy (VS) in monolayer WS2 have observed that in-gap defect states feature prominent sideband structure, a signature of strong electron-phonon (el-ph) interactions. Here, we use a combination of density functional theory (DFT) and ab initio many-body perturbation theory within the GW approximation to calculate defect states associated with VS in monolayer WS2 and their el-ph interactions. For each vibrational state, we compute Huang-Rhys factors via first-principles including spin-orbit coupling (SOC) in a fully relativistic way. We find that just a few specific phonon modes couple strongly with the defect levels and that two defect levels split by SOC couple to the same modes, but different strengths. We also find that inclusion of exact exchange and electron-electron correlations using the GW method substantially renormalizes the coupling strength in a mode-dependent fashion, giving rise to better agreement with experimental spectral lineshapes. This work enables a deeper understanding of el-ph interactions in systems that feature localized electronic states and provides a route for predicting spectral features associated with defects with higher accuracy using first-principles calculations.

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Presenters

  • Jun-Ho Lee

    University of California, Berkeley; Lawrence Berkeley National Laboratory

Authors

  • Jun-Ho Lee

    University of California, Berkeley; Lawrence Berkeley National Laboratory

  • Jonah B Haber

    University of California, Berkeley, University of California, Berkeley; Lawrence Berkeley National Laboratory, Department of Physics, University of California, Berkeley, Department of Physics, University of California, Berkeley, CA 94720; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.

  • Jeffrey B Neaton

    Lawrence Berkeley National Laboratory, University of California, Berkeley; Lawrence Berkeley National Laboratory; Kavli Energy NanoSciences Institute at Berkeley, Department of Physics, University of California, Berkeley; Materials Sciences Division, Lawrence Berkeley National Laboratory; Kavli Energy NanoScience Institute at Berkeley, Department of Physics, University of California, Berkeley, CA 94720; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Kavli Energy Nano