NUM2BEC · Number Conserving Approaches to Bose-Einstein Condensates

Bose-Einstein condensation is the coalescence of a macroscopic number of boson atoms into the same quantum state. As such they are manifestations of a quantum effect on a macroscopic scale possessing many interesting and intriguing properties. Recent advances in experimental techniques have meant that many fundamental quantum phenomena can be explored through a Bose-Einstein condensate. When these systems are out-of-equilibrium they exhibit non-trivial dynamics that are highly dependent on quantum fluctuations around the condensed ground state. This project will use a number conserving approach to understand aspects of quantum fluctuations in out-of-equilibrium Bose-Einstein condensates in two cases that are theoretically and experimentally important: the effect of a non-zero temperature field and the dynamics at the interface in a mixture of condensates. It will then utilise these two cases to investigate the fundamental limit of metrology, using the Bose-Einstein condensate as the ‘test-bed’.""