Pascal Bugnion, Gareth Conduit, Richard Needs
Ultracold atomic gases provide a test bed for the study of fundamental quantum condensed matter phenomena. We are particularly interested in fermionic cold atom gases as these can be used to model collective electronic processes in the solid state.
The dynamics of a dilute ultracold atomic gas is dominated by short-range interactions between the atoms, typically characterized by the scattering length of the inter-particle potential. Modelling this regime is challenging for QMC methods as the wave function diverges when particles coalesce.
Previous attempts at circumventing this divergence have normally involved using an effective potential to model the inter-particle interactions. This effective potential is constructed to reproduce some of the features of the true potential while avoiding its pathological behaviour. We investigate the applicability of the wide range of methods developed by the electronic structure and chemistry community to the development of an effective potential for interactions between cold atoms.