Some of the simplest systems accessible to experiments with ultracold gases in optical lattices are dimers: atoms in a double-well optical lattice, or atoms in a single optical trap, but with two interacting spin states. These systems are very accurately represented by the Bose-Hubbard dimer. A quantum model with many degrees of freedom, the Bose-Hubbard dimer can be approximated by classical equations of motion for just two variables, z, the imbalance in the two wells' atomic populations, and phi, the wells' relative phase. We study how much of the quantum system's behavior is captured by this simple classical picture. Surprisingly, the classical model not only predicts the dynamics of z and phi, but also contains information about the entanglement of the modes. It can therefore be used to shed light on the counterintuitive technique of enhancing entanglement though controlled dissipation. Further features of the quantum model can be recovered through semiclassical quantization of the equations of motion. This approach allows us to obtain closed-form, nonperturbative estimates of the tunneling rate between the modes.

Hosts: Harold Baranger and Josh Socolar

# The Dynamics of a (Dissipative) Bose-Hubbard Dimer

Condensed Matter Seminar

Ted Pudlik (Boston Univ & Duke)

Thursday, March 27, 2014 - 11:30am

location:

Physics 298

contact:

Paul, Cristin

660-2491