Speaker
Marcus Kollar
(University of Augsburg)
Description
A quantum many-body system which is prepared in the ground state of an integrable Hamiltonian will not directly thermalize after a sudden small parameter quench away from integrability. Rather, it will be trapped in a prethermalized state and can thermalize only at a later stage, as observed after an interaction quench in the Hubbard model. We show that the prethermalization stage can be described by a generalized Gibbs ensemble built from approximate constants of motion in the vicinity of the integrable point. For the second stage we derive a quantum Boltzmann equation that describes the crossover from the prethermalized to the thermalized state. For nearly integrable systems this two-stage scenario provides an understanding of thermalization from a pure initial state to a final thermal ensemble state.
Author
Marcus Kollar
(University of Augsburg)
