Abstract
For a Bose-Hubbard dimer, we study quenches of the site energy imbalance, taking a highly asymmetric Hamiltonian to a fully symmetric one. The ramp is carried out over a finite time that interpolates between the instantaneous and adiabatic limits. We provide results for the excess energy of the final state compared to the ground-state energy of the final Hamiltonian as a function of the quench rate. This excess energy serves as the analog of the defect density that is considered in the Kibble-Zurek picture of ramps across phase transitions. We also examine the fate of quantum “self-trapping” when the ramp is not instantaneous.
- Received 20 January 2010
DOI:https://doi.org/10.1103/PhysRevB.81.054305
©2010 American Physical Society