Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 45: Correlated Electrons: Nonequilibrium Quantum Many-Body Systems 3 (jointly with DY)

TT 45.2: Vortrag

Dienstag, 17. März 2015, 14:15–14:30, H 3010

Measure of equilibration in Luttinger liquids — •Mariya Medvedyeva and Stefan Kehrein — Goettingen University, Goettingen, Germany

We consider the properties of the Luttinger liquid in the echo protocol (forward evolution in time followed by the backward evolution of slightly perturbed system) and explore the relation of the Loschmidt echo (the overlap of the initial and final wavefunctions) and the measurable properties of the system. We first study the linear Luttinger liquid as an example of an integrable system and find that the momentum distribution function exhibits almost complete recurrence while the Loschmidt echo does not, as the diagonal basis is different during the forward and backward time evolution. For a nonlinear Luttinger liquid the recurrence strength of the momentum distribution function drops as the nonlinearity of the fermion dispersion relation grows. We conclude that there is no simple relation of the Loschmidt echo to the behavior of the observables and that more work is needed to understand how to interpret the echo in the context of experiment.