title: Local versus global equilibration near the bosonic Mott-insulator-superfluid transition.
abstract: We study the time scales for adiabaticity of trapped cold bosons subject to a time-varying lattice potential using a dynamic Gutzwiller mean-field theory. We explain apparently contradictory experimental observations by demonstrating a clear separation of time scales for local dynamics (~ ms) and global mass redistribution (~1 s). We provide a simple explanation for the short and fast time scales, finding that while density or energy transport is dominated by low energy phonons, particle-hole excitations set the adiabaticity time for fast ramps. We show how mass transport shuts off within Mott-insulator domains, leading to a chemical potential gradient that fails to equilibrate on experimental time scales.
authors.affiliation: Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA. ssn8@cornell.edu
authors.forename: Stefan S
authors.initials: SS
authors.lastname: Natu
authors.forename: Kaden R A
authors.initials: KR
authors.lastname: Hazzard
authors.forename: Erich J
authors.initials: EJ
authors.lastname: Mueller