Dynamical downfolding for localized quantum states

Journal Article · Wed Jul 19 00:00:00 UTC 2023 · npj Computational Materials

DOI: https://doi.org/10.1038/s41524-023-01078-5 · OSTI ID:1991434

Romanova, Mariya  ^[1]; Weng, Guorong  ^[1]; Apelian, Arsineh ^[1]; Vlček, Vojtěch  ^[1]

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1. University of California, Santa Barbara, CA (United States)

We introduce an approach to treat localized correlated electronic states in the otherwise weakly correlated host medium. Here, the environment is dynamically downfolded on the correlated subspace. It is captured via renormalization of one and two quasiparticle interaction terms which are evaluated using many-body perturbation theory. We outline the strategy on how to take the dynamical effects into account by going beyond the static limit approximation. Further, we introduce an efficient stochastic implementation that enables treating the host environment with a large number of electrons at a minimal computational cost. For a small explicitly correlated subspace, the dynamical effects are critical. We demonstrate the methodology by reproducing optical excitations in the negatively charged NV center defect in diamond, that agree with experimental results.

• Research Organization: University of California, Santa Barbara, CA (United States)
• Sponsoring Organization: California NanoSystems; Chinese Academy of Sciences; National Science Foundation; USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR). Scientific Discovery through Advanced Computing (SciDAC); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
• Grant/Contract Number: AC02-05CH11231; SC0022198
• OSTI ID: 1991434
• Journal Information: npj Computational Materials, Journal Name: npj Computational Materials Journal Issue: 1 Vol. 9; ISSN 2057-3960
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United Kingdom
• Language: English