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TT: Fachverband Tiefe Temperaturen
TT 24: Correlated Electrons: (General) Theory 2
TT 24.7: Vortrag
Mittwoch, 25. März 2009, 11:30–11:45, HSZ 301
Time evolution of correlations in strongly interacting fermions after a quantum quench — •Salvatore R. Manmana1, Stefan Wessel2, Reinhard M. Noack3, and Alejandro Muramatsu2 — 1Institute of Theoretical Physics (CTMC), EPF Lausanne, CH-1015 Lausanne, Schweiz — 2Institut für Theoretische Physik III, Universität Stuttgart — 3Fachbereich Physik, Philipps-Universität Marburg
Using the adaptive time-dependent density matrix renormalization group, we study the time evolution of density correlations of interacting spinless fermions on a one-dimensional lattice after a sudden change in the interaction strength. Over a broad range of model parameters, the correlation function exhibits a characteristic light-cone-like time evolution representative of a ballistic transport of information. Such behavior is observed both when quenching an insulator into the metallic region and also when quenching within the insulating region. However, when a metallic state beyond the quantum critical point is quenched deep into the insulating regime, no indication for ballistic transport is observed. Instead, stable domain walls in the density correlations emerge during the time evolution, consistent with the predictions of the Kibble-Zurek mechanism.