Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 71: Correlated Electrons: Poster Session
TT 71.11: Poster
Mittwoch, 18. März 2015, 15:00–18:00, Poster B
Nonequilibrium dynamics of the pseudo gap single impurity Anderson model — •Julian Mußhoff1, Christian Kleine2, and Frithjof B. Anders2 — 1Forschungszentrum Jülich GmbH, Institute for Advanced Simulation, 52425 Jülich, Germany — 2Technische Universität Dortmund, Lehrstuhl für Theoretische Physik II, 44221 Dortmund, Germany
In the single impurity Anderson model with a pseudo-gap density of states, modeled by a power law ρ(є) ∝ |є|r, a local moment phase and a strong coupling phase are separated by a quantum critical point (QCP). We investigate the real-time dependence of the double occupancy of the impurity due to quenches in one phase and over the QCP using the time-dependent numerical renormalization group (TD-NRG). We show that the double occupancy equilibrates to a steady state for long times. We present a time-dependent perturbation theory which becomes exact at short times. The short-time evolution of our TD-NRG data excellently agrees with this perturbation theory providing an analytical expression of the relevant time scales for the short-time dynamics. We are able to trace back the differences between the results obtained by a time-dependent Gutzwiller variational approach and by the TD-NRG to the wave-function ansatz in the Gutzwiller approach.