Density matrix embedding: A simple alternative to dynamical mean-field theory

Gerald Knizia, Garnet Kin Lic Chan

Research output: Contribution to journalArticlepeer-review

202 Scopus citations

Abstract

We introduce density matrix embedding theory (DMET), a quantum embedding theory for computing frequency-independent quantities, such as ground-state properties, of infinite systems. Like dynamical mean-field theory, DMET maps the bulk interacting system to a simpler impurity model and is exact in the noninteracting and atomic limits. Unlike dynamical mean-field theory, DMET is formulated in terms of the frequency-independent local density matrix, rather than the local Green's function. In addition, it features a finite, algebraically constructible bath of only one bath site per impurity site, with no bath discretization error. Frequency independence and the minimal bath make DMET a computationally simple and efficient method. We test the theory in the one-dimensional and two-dimensional Hubbard models at and away from half filling, and we find that compared to benchmark data, total energies, correlation functions, and metal-insulator transitions are well reproduced, at a tiny computational cost.

Original languageEnglish (US)
Article number186404
JournalPhysical review letters
Volume109
Issue number18
DOIs
StatePublished - Nov 2 2012

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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