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DOE OSTI · 1958168

Dynamic mode decomposition for extrapolating nonequilibrium Green's-function dynamics

Reeves, Cian C.·Yin, Jia·Zhu, Yuanran·Ibrahim, Khaled Z.·Yang, Chao·Vlček, Vojtěch
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Abstract

The Hartree-Fock generalized Kadanoff-Baym ansatz (HF-GKBA) offers an approximate numerical procedure for propagating the two-time nonequilibrium Green's function (NEGF). Here, using the GW self-energy, we compare the HF-GKBA to exact results for a variety of systems with long- and short-range interactions, different two-body interaction strengths, and various nonequilibrium preparations. We find excellent agreement between the HF-GKBA and exact time evolution in models when more realistic long-range exponentially decaying interactions are considered. Furthermore, this agreement persists for long times and for intermediate to strong interaction strengths. In large systems, HF-GKBA becomes prohibitively expensive for long-time evolutions. For this reason, we look at the use of dynamical mode decomposition (DMD) to reconstruct long-time NEGF trajectories from a sample of the initial trajectory. Using no more than 16% of the total time evolution, we reconstruct the total trajectory with high fidelity. Our results show the potential for DMD to be used in conjunction with HF-GKBA to calculate long-time trajectories in large-scale systems.

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75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYApproximation methods for many-body systemsElectronic structureFirst-principles calculationsGW methodGreen's function methodsMany-body techniques

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Reeves, Cian C., Yin, Jia, Zhu, Yuanran, Ibrahim, Khaled Z., Yang, Chao, Vlček, Vojtěch. 2023-02-03. Dynamic mode decomposition for extrapolating nonequilibrium Green's-function dynamics. https://doi.org/10.1103/physrevb.107.075107

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