Quantum chaos with a Bose-Einstein condensate

Abstract

Scope and Method of Study: The purpose of this research was to experimentally study a quantum delta-kicked accelerator utilizing a Bose Einstein condensate (BEC) of Rb87 atoms. An all optical method was chosen to create a BEC. Generalization of the quantum theory of the quantum accelerator modes to include the higher order QAM's observed in cold atomic systems was also among the topics studied in this research.

Findings and Conclusions: The underlying pseudoclassical phase space structure of the quantum delta-kicked accelerator was experimentally explored. This was achieved by exposing a Bose-Einstein condensate to a spatially corrugated potential created by pulses of an off-resonant standing light wave. For the first time quantum accelerator modes were realized in such a system. By utilizing the narrow momentum distribution of the condensate the discrete momentum state structure of a quantum accelerator mode was observed. These experiments allowed us to directly measure the size of the structures in the phase space of the delta-kicked accelerator.

We also found that the phase space structures in the pseudoclassical model are given by the interference of the different momentum diffraction orders of the matter wave from standing light waves. This discovery allowed us to generalize the quantum theory of accelerator modes to explain higher order accelerator modes observed in cold atomic systems.