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arXiv · 1310.4151

Green's functions from real-time bold-line Monte Carlo: spectral properties of the nonequilibrium Anderson impurity model

Guy Cohen·Emanuel Gull·David R. Reichman·Andrew J. Millis
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Abstract

The nonequilibrium spectral properties of the Anderson impurity model with a chemical potential bias are investigated within a numerically exact real time quantum Monte Carlo formalism. The two-time correlation function is computed in a form suitable for nonequilibrium dynamical mean field calculations. Additionally, the evolution of the model's spectral properties are simulated in an alternative representation, defined by a hypothetical but experimentally realizable weakly coupled auxiliary lead. The voltage splitting of the Kondo peak is confirmed and the dynamics of its formation after a coupling or gate quench are studied. This representation is shown to contain additional information about the dot's population dynamics. Further, we show that the voltage-dependent differential conductance gives a reasonable qualitative estimate of the equilibrium spectral function, but significant qualitative differences are found including incorrect trends and spurious temperature dependent effects.

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Guy Cohen, Emanuel Gull, David R. Reichman, Andrew J. Millis. 2014-04-10. Green's functions from real-time bold-line Monte Carlo: spectral properties of the nonequilibrium Anderson impurity model. https://doi.org/10.1103/physrevlett.112.146802

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