Dynamics-induced freezing of strongly correlated ultracold bosons
1 Theoretical Physics Department, Indian Association for the Cultivation of Science Jadavpur, Kolkata-700032, India
2 Department of Physics, California Institute of Technology - Pasadena, CA 91125, USA
Received: 23 August 2012
Accepted: 27 November 2012
We study the non-equilibrium dynamics of ultracold bosons in an optical lattice with a time-dependent hopping amplitude J(t) = J0 + δJcos(ωt) which takes the system from a superfluid phase near the Mott-superfluid transition (J = J0 + δJ) to a Mott phase (J = J0 − δJ) and back through a quantum critical point (J = Jc), and demonstrate dynamics-induced freezing of the boson wave function at specific values of ω. At these values, the wave function overlap F (defect density P = 1 − F) approaches unity (zero). We provide a qualitative explanation of the freezing phenomenon, show its robustness against quantum fluctuations and the presence of a trap, compute residual energy and superfluid order parameter for such dynamics, and suggest experiments to test our theory.
PACS: 05.30.Jp – Boson systems / 64.60.Ht – Dynamic critical phenomena / 05.30.Rt – Quantum phase transitions
© EPLA, 2012