Role of trap-induced scales in non-equilibrium dynamics of strongly interacting trapped bosons

Abstract

We use a time-dependent hopping expansion technique to study the non-equilibrium dynamics of strongly interacting bosons in an optical lattice in the presence of a harmonic trap characterized by a force constant K. We show that after a sudden quench of the hopping amplitude J across the superfluid (SF)-Mott insulator (MI) transition, the SF order parameter | δr(t)| and the local density fluctuation Δnr(t) exhibit sudden decoherence beyond a trapinduced time scale T0∼K- / 1 2. We also show that after a slow linear ramp down of J, |δr | and the boson defect density Pr display a novel non-monotonic spatial profile. Both these phenomena can be explained as consequences of trap-induced time and length scales affecting the dynamics and can be tested by concrete experiments.