MSc Thesis Presentation: Diffusion Monte Carlo study of strongly interacting two-dimensional Fermi gases

MSc Thesis Presentation

Candidate: Alexander Galea

Abstract

Ultracold atomic Fermi gases have been a popular topic of research, with attention being paid recently to two-dimensional (2D) gases.  The interaction strength between spin-up and spin-down particles in two-component Fermi gases can be tuned in experiments, allowing for a strongly interacting regime where the gas properties are yet to be fully understood.  We have probed this regime for 2D Fermi gases by performing T = 0 ab initio diffusion Monte Carlo (DMC) calculations.  This required us to first solve the two-body scattering problem in 2D.  To accurately account for interactions at the many-body level, we use complicated wave functions containing variable parameters that were optimized with variational Monte Carlo energy minimization.  Our optimized wave functions were used in DMC to determine ground-state properties of the gas over a range of interaction strengths.  We have calculated the energy per particle, Tan's contact parameter, the chemical potential, and the pairing gap.

Examination Committee:

Dr. Robert Wickham, Chair

Dr. Carl Svensson, Advisory Committee

Dr. Alexandros Gezerlis, Advisory Committee