Nonequilibrium dynamical mean-field calculations based on the noncrossing approximation and its generalizations
Year: 2010
Type: article
Abstract: We solve the impurity problem which arises within nonequilibrium dynamical mean-field theory for the Hubbard model by means of a self-consistent perturbation expansion around the atomic limit. While the lowest order, known as the noncrossing approximation (NCA), is reliable only when the interaction $U$ is much larger than the bandwidth, low-order corrections to the NCA turn out to be sufficient to reproduce numerically exact Monte Carlo results in a wide parameter range that covers the insulating phase and the metal-insulator crossover regime at not too low temperatures. As an application of the perturbative strong-coupling impurity solver we investigate the response of the double occupancy in the Mott insulating phase of the Hubbard model to a dynamical change in the interaction or the hopping, a technique which has been used as a probe of the Mott insulating state in ultracold fermionic gases.
Source: Physical Review B
Authors: Martin Eckstein, Philipp Werner
Institutions: ETH Zurich, Institute for Theoretical Physics
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2075658311