Death at the Band Edge - where Degenerate Bose Gases Degenerate

The Dodd-Walls Centre for Quantum Science & Technology Physics Department, University of Otago, New Zealand

Monday 27 October 2008, 3:30 pm, Lecture Theatre EN101, EN Building, Hawthorn.

Of all the important discoveries and applications that have come from ultracold atom research, perhaps the most useful to the physics community overall are those that have provided a detailed understanding of the quantum physics at the heart of a wide range of important phenomena in other physical systems. One of the best examples of this is Bose-Einstein condensates in optical lattices, which have been used to model the behaviour of electrons in crystalline solids. Bose condensates in optical lattices are attractive systems with which to study this aspect of solid-state physics because the experiments provide an exceptional level of flexibility and control, and there are microscopic theories available that are computationally tractable with various degrees of approximation.

At sufficiently large densities the inter-atomic interactions result in a rich range of nonlinear phenomena. Notably, the quantum phase transition from a superfluid to a Mott insulator and the generation of bright gap solitons have been observed. When the condensate is moving relative to the lattice, the nonlinearity can induce a dynamical or modulational instability that leads to an observed heating of the condensate. This talk will present an investigation into one such dynamical instability.

The research I will describe is part of the newly formed Dodd-Walls Centre (DWC), which links together all of New Zealand's expertise in quantum optics, ultracold atoms, and photonics. I will provide an overview of the DWC.

Back to 2008 programme