The Open Bose-Hubbard Dimer
This event is part of the PhD Final Oral Exams.
Dissertation Committee: David K. Campbell, Anatoli Polkovnikov, Claudio Chamon, Anna Swan, Emanuel Katz
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, the imbalance in the two wells' atomic populations, and the wells' relative phase. We discuss how much of the quantum system's behavior is captured by this simple classical picture, and use semiclassical quantization to derive analytical corrections to it.
A dissipative bosonic dimer is also an approximate quantum model for the magnetron, a type of vacuum tube microwave source. We use it to study magnetron operation for small device sizes (relative to the magnetic length) and low fields, when quantum effects such as the wave nature of the electron or spontaneous emission cannot be neglected.