Efficient Perturbation Theory for Quantum Lattice Models

Link:

https://doi.org/10.1103/PhysRevLett.102.206401

Autor/in:

Erscheinungsjahr:

2009

Medientyp:

Text

Beschreibung:

We present a novel approach to long-range correlations beyond dynamical mean-field theory, through a ladder approximation to dual fermions. The new technique is applied to the two-dimensional Hubbard model. We demonstrate that the transformed perturbation series for the nonlocal dual fermions has superior convergence properties over standard diagrammatic techniques. The critical Néel temperature of the mean-field solution is suppressed in the ladder approximation, in accordance with quantum Monte Carlo results. An illustration of how the approach captures and allows us to distinguish short- and long-range correlations is given. © 2009 The American Physical Society.

Lizenz:

info:eu-repo/semantics/closedAccess

Quellsystem:

Forschungsinformationssystem der UHH

Interne Metadaten

Quelldatensatz: oai:www.edit.fis.uni-hamburg.de:publications/80a650c0-cfef-4647-8e81-07cac3e9e88e