SKM 2023 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 20: Focus Session: Frontiers of Electronic-Structure Theory I (joint session O/HL)
HL 20.3: Talk
Tuesday, March 28, 2023, 11:00–11:15, TRE Ma
GW multipole approach for the frequency description of the dielectric screening — •Claudia Cardoso1, Dario A. Leon2, Andrea Ferretti1, Daniele Varsano1, and Elisa Molinari1 — 1S3 Centre, Istituto Nanoscienze, CNR, 41125, Modena (Italy) — 2Department of Mechanical Engineering and Technology Management, Norwegian University of Life Sciences, 1430, Ås (Norway)
In the present work, we discuss a numerical approach for GW calculations that takes into account the frequency dependence of the screening via a multi-pole approximation (MPA), an accurate and efficient alternative to current full-frequency methods, that overcomes several limitations of the plasmon pole approximation (PPA).
MPA was recently developed and validated for semiconductors[1]. We now extend the use of MPA to metallic systems by optimizing the frequency sampling for these class of materials and propose a simple method to include the zero q limit of the intra-band contributions. The good agreement between MPA and full frequency results for the calculations of quasi-particle energies, polarizability, self-energy and spectral functions in different metallic systems confirms the accuracy and computational efficiency of the method. Finally, we discuss the physical interpretation of the MPA poles through a comparison with experimental electron energy loss spectra for Cu.
[1] D. A. Leon, C. Cardoso, T. Chiarotti, D. Varsano, E. Molinari, A. Ferretti, Phys. Rev. B 104, 115157