Sweeping from the superfluid to the Mott phase in the Bose-Hubbard model.
We study the sweep through the quantum phase transition from the superfluid to the Mott state for the Bose-Hubbard model with a time-dependent tunneling rate J(t). In the experimentally relevant case of exponential decay J(t) proportional variant e -gamma t, an adapted mean-field expansion for large fillings n yields a scaling solution for the fluctuations. This enables us to analytically calculate the evolution of the number and phase variations (on-site) and correlations (off-site) for slow (gamma<<mu), intermediate, and fast (nonadiabatic gamma>>mu) sweeps, where mu is the chemical potential. Finally, we derive the dynamical decay of the off-diagonal long-range order as well as the temporal shrinkage of the superfluid fraction in a persistent ring-current setup.
Schützhold
Ralf
R
Institut für Theoretische Physik, Technische Universität Dresden, D-01062 Dresden, Germany. schuetz@theory.phy.tu-desden.de
Uhlmann
Michael
M
Xu
Yan
Y
Fischer
Uwe R
UR