Memory-Efficient Nonequilibrium Green's Function Framework Built On Quantics Tensor Trains

Fuente: arXiv
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Main Authors: Środa, Maksymilian, Inayoshi, Ken, Shinaoka, Hiroshi, Werner, Philipp
Format: Preprint
Published: 2024
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author Środa, Maksymilian
Inayoshi, Ken
Shinaoka, Hiroshi
Werner, Philipp
author_facet Środa, Maksymilian
Inayoshi, Ken
Shinaoka, Hiroshi
Werner, Philipp
contents One of the challenges in diagrammatic simulations of nonequilibrium phenomena in lattice models is the large memory demand for storing momentum-dependent two-time correlation functions. This problem can be overcome with the recently introduced quantics tensor train (QTT) representation of multivariable functions. Here, we demonstrate nonequilibrium Green's function simulations within the $GW$ and Migdal approximations with high momentum resolution, up to times which exceed the capabilities of standard implementations and are long enough to study, e.g., transient Floquet physics during multi-cycle electric field pulses and thermalization dynamics. The self-consistent calculation on the three-leg Kadanoff-Baym contour is fully self-contained, employing only QTT-compressed functions and input functions which are either generated directly in QTT form or obtained via quantics tensor cross interpolation.
format Preprint
id arxiv_https___arxiv_org_abs_2412_14032
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Memory-Efficient Nonequilibrium Green's Function Framework Built On Quantics Tensor Trains
Środa, Maksymilian
Inayoshi, Ken
Shinaoka, Hiroshi
Werner, Philipp
Strongly Correlated Electrons
One of the challenges in diagrammatic simulations of nonequilibrium phenomena in lattice models is the large memory demand for storing momentum-dependent two-time correlation functions. This problem can be overcome with the recently introduced quantics tensor train (QTT) representation of multivariable functions. Here, we demonstrate nonequilibrium Green's function simulations within the $GW$ and Migdal approximations with high momentum resolution, up to times which exceed the capabilities of standard implementations and are long enough to study, e.g., transient Floquet physics during multi-cycle electric field pulses and thermalization dynamics. The self-consistent calculation on the three-leg Kadanoff-Baym contour is fully self-contained, employing only QTT-compressed functions and input functions which are either generated directly in QTT form or obtained via quantics tensor cross interpolation.
title Memory-Efficient Nonequilibrium Green's Function Framework Built On Quantics Tensor Trains
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2412.14032