Local Versus Global Equilibration near the Bosonic Mott-Insulator–Superfluid Transition

Stefan S. Natu, Kaden R. A. Hazzard, Erich J. Mueller
2011 Physical Review Letters  
We study the response of trapped two dimensional cold bosons to time dependent lattices. We find that in lattice ramps from 11 (superfluid, ħ/U_i = 3ms, ħ/J_i = 45ms) to 16 recoils (Mott, ħ/U_f = 2ms, ħ/J_f = 130ms) the local number fluctuations remains at their equilibrium values if ramps are slower than 3 ms. Global transport, however, is much slower (1s), especially in the presence of Mott shells. This separation of timescales has practical implications for cold atom experiments and cooling protocols.
doi:10.1103/physrevlett.106.125301 pmid:21517320 fatcat:zdajub7owvhl7emxspkrsbigs4