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arXiv · 1005.1872

Nonequilibrium dynamical mean-field calculations based on the non-crossing approximation and its generalizations

Martin Eckstein·Philipp Werner
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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 non-crossing 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 of the interaction or the hopping, a technique which has been used as a probe of the Mott insulating state in ultracold fermionic gases.

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Martin Eckstein, Philipp Werner. 2010-05-11. Nonequilibrium dynamical mean-field calculations based on the non-crossing approximation and its generalizations. https://doi.org/10.1103/physrevb.82.115115

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