Projective purification of correlated reduced density matrices

In the search for accurate approximate solutions of the many-body Schrödinger equation, reduced density matrices play an important role, as they allow one to formulate approximate methods with polynomial scaling in the number of particles. However, these methods frequently encounter the issue of N-r...

Full description

Saved in:
Bibliographic Details
Main Authors: Elias Pescoller, Marie Eder, Iva Březinová
Format: Article
Language:English
Published: American Physical Society 2025-02-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.7.013211
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849765235550846976
author Elias Pescoller
Marie Eder
Iva Březinová
author_facet Elias Pescoller
Marie Eder
Iva Březinová
author_sort Elias Pescoller
collection DOAJ
description In the search for accurate approximate solutions of the many-body Schrödinger equation, reduced density matrices play an important role, as they allow one to formulate approximate methods with polynomial scaling in the number of particles. However, these methods frequently encounter the issue of N-representability, whereby in self-consistent applications of the methods, the reduced density matrices become unphysical. A number of algorithms have been proposed in the past to restore a given set of N-representability conditions once the reduced density matrices become defective. However, these purification algorithms either have ignored symmetries of the Hamiltonian related to conserved quantities or have not incorporated them in an efficient way, thereby modifying the reduced density matrix to a greater extent than is necessary. In this paper, we present an algorithm capable of efficiently performing all of the following tasks in the least invasive manner: restoring a given set of N-representability conditions, maintaining contraction consistency between successive orders of reduced density matrices, and preserving all conserved quantities. We demonstrate the superiority of the present purification algorithm over previous ones in the context of the time-dependent two-particle reduced density matrix method applied to the quench dynamics of the Fermi-Hubbard model.
format Article
id doaj-art-def3c8bb60a548d88e4a76fbd8a828fd
institution DOAJ
issn 2643-1564
language English
publishDate 2025-02-01
publisher American Physical Society
record_format Article
series Physical Review Research
spelling doaj-art-def3c8bb60a548d88e4a76fbd8a828fd2025-08-20T03:04:55ZengAmerican Physical SocietyPhysical Review Research2643-15642025-02-017101321110.1103/PhysRevResearch.7.013211Projective purification of correlated reduced density matricesElias PescollerMarie EderIva BřezinováIn the search for accurate approximate solutions of the many-body Schrödinger equation, reduced density matrices play an important role, as they allow one to formulate approximate methods with polynomial scaling in the number of particles. However, these methods frequently encounter the issue of N-representability, whereby in self-consistent applications of the methods, the reduced density matrices become unphysical. A number of algorithms have been proposed in the past to restore a given set of N-representability conditions once the reduced density matrices become defective. However, these purification algorithms either have ignored symmetries of the Hamiltonian related to conserved quantities or have not incorporated them in an efficient way, thereby modifying the reduced density matrix to a greater extent than is necessary. In this paper, we present an algorithm capable of efficiently performing all of the following tasks in the least invasive manner: restoring a given set of N-representability conditions, maintaining contraction consistency between successive orders of reduced density matrices, and preserving all conserved quantities. We demonstrate the superiority of the present purification algorithm over previous ones in the context of the time-dependent two-particle reduced density matrix method applied to the quench dynamics of the Fermi-Hubbard model.http://doi.org/10.1103/PhysRevResearch.7.013211
spellingShingle Elias Pescoller
Marie Eder
Iva Březinová
Projective purification of correlated reduced density matrices
Physical Review Research
title Projective purification of correlated reduced density matrices
title_full Projective purification of correlated reduced density matrices
title_fullStr Projective purification of correlated reduced density matrices
title_full_unstemmed Projective purification of correlated reduced density matrices
title_short Projective purification of correlated reduced density matrices
title_sort projective purification of correlated reduced density matrices
url http://doi.org/10.1103/PhysRevResearch.7.013211
work_keys_str_mv AT eliaspescoller projectivepurificationofcorrelatedreduceddensitymatrices
AT marieeder projectivepurificationofcorrelatedreduceddensitymatrices
AT ivabrezinova projectivepurificationofcorrelatedreduceddensitymatrices