Slow quench dynamics of periodically driven quantum gases

We study the evolution of bosons in a periodically driven optical lattice during a slow change of the driving amplitude. Both the regime of high frequency and low frequency driving are investigated. In the low frequency regime, resonant absorption of energy is observed. In the high frequency regime, the dynamics is compared to a system with an effective Hamiltonian in which the atoms are dressed' by the driving field. This dressing’ can dramatically change the amplitude and sign of the effective tunneling. A particular focus of this study is the investigation of the time-scales necessary for the evolving quantum state to follow almost adiabatically to the ground-state of the effective many body system.