Regensburg 2022 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 12: Computational Materials Modelling: Physics of Ensembles 1
MM 12.8: Talk
Tuesday, September 6, 2022, 12:15–12:30, H44
Wannier function perturbation theory: localized representation and interpolation of wavefunction perturbation — •Jae-Mo Lihm and Cheol-Hwan Park — Department of Physics, Seoul National University, Seoul, Korea
Wannier functions provide a localized representation of the electronic structure of solids and are thus finds wide application in condensed matter physics. However, the Wanneier function method is limited in that it cannot be used to represent the change of the wavefunctions due to perturbations. In this work, we introduce Wannier function perturbation theory (WFPT) [1], which overcomes this limitation by providing a localized representation of wavefunction perturbation which we term “Wannier function perturbation.” Among the diverse possible applications of WFPT, we provide three examples. First, we calculate the temperature dependence of the indirect optical absorption spectra of silicon. Our calculation differentiates phonon-absorption and phononemission processes and includes the band-gap renormalization without arbitrary temperature-dependent shifts in energy at the same time, which is beyond reach of existing methods. Second, we develop a theory for calculating the shift spin current without any band-truncation error and apply it to monolayer WTe2. Third, we apply WFPT to calculate the spin Hall conductivity of the same material, again without any band-truncation error. WFPT will open up a new way for studying the response properties of the electron states in real materials.
[1] J.-M. Lihm and C.-H. Park, Phys. Rev. X, 11, 041053 (2021)