Dynamical self-stabilization of the Mott insulator: Time evolution of the density and entanglement entropy of out-of-equilibrium cold fermion gases

¹ Mathematical Physics and European Theoretical Spectroscopy Facility, Lund University - 22100 Lund, Sweden, EU
² Instituto de Física de São Carlos, Universidade de São Paulo - São Carlos, 13560-970 São Paulo, Brazil
³ Centro de Ciências Naturais e Humanas, Universidade Federal do ABC - Santo André, 09210-170 São Paulo, Brazil

Received: 5 July 2010
Accepted: 10 January 2011

Abstract

The time evolution of the out-of-equilibrium Mott insulator is investigated numerically through calculations of space-time–resolved density and entropy profiles resulting from the release of a gas of ultracold fermionic atoms from an optical trap. For adiabatic, moderate and sudden switching-off of the trapping potential, the out-of-equilibrium dynamics of the Mott insulator is found to differ profoundly from that of the band insulator and the metallic phase, displaying a self-induced stability that is robust within a wide range of densities, system sizes and interaction strengths. The connection between the entanglement entropy and changes of phase, known for equilibrium situations, is found to extend to the out-of-equilibrium regime. Finally, the relation between the system's long time behavior and the thermalization limit is analyzed.