Dresden 2009 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 24: Correlated Electrons: (General) Theory 2

TT 24.6: Vortrag

Mittwoch, 25. März 2009, 11:15–11:30, HSZ 301

Adiabatic parameter change across the metal-insulator transition in the Falicov-Kimball model — •Martin Eckstein and Marcus Kollar — Theoretische Physik III, Zentrum für Elektronische Korrelationen und Magnetismus, Universität Augsburg, 86153 Augsburg

We obtain the exact time evolution of the fermionic Falicov-Kimball model during a slow variation of the interaction parameter, using dynamical mean-field theory (DMFT) for nonequilibrium. For this purpose we adapt the DMFT equations which were derived for a sudden interaction quench [1] and solve them numerically. We analyze the dependence of the excitation energy on the ramp speed in the adiabatic limit, and find different power laws when the system is driven within the insulating phase, within the metallic phase, or between the two phases. Possible reasons for this behavior are discussed.

[1] M. Eckstein and M. Kollar, Phys. Rev. Lett. 100, 120404 (2008).