Séminaire du LPTMS: Jacopo de Nardis

Non-equilibrium quantum mechanics has received a considerable attention in the last years and in particular the dynamics observed after a quantum quench, when a global parameter in the Hamiltonian of the system is rapidly changed. We focus here on the post-quench time evolution of the simplest interacting integrable models as the Lieb-Liniger delta-Bose gas and the spin-1/2 XXZ spin chain. We address the problem of determining the steady state after a quench in the interaction strength and the time evolution towards it. While the steady state is determined by sets of recently introduced quasi-local conserved quantities, the time evolution is related to the thermodynamic limit of the matrix elements and of the overlap coefficients between the eigenstates of the model and the initial state.