Condensed Matter Seminars

Fermion pairing leads to interesting phenomena in many physical systems, whether the constituents are atoms, nucleons, electrons, or quarks. The newfound ability to trap and cool fermionic atoms has provided a versatile avenue for experimental exploration of fermion pairing. I have been working on using field theory techniques to describe and calculate properties of these gases. In this talk, I focus on a dilute gas of 2-component, nonrelativistic fermions whose scattering length is much larger than the average interparticle spacing. This is a setup which describes atomic gases tuned to a Feshbach resonance, as well as neutron matter. I discuss how Monte Carlo methods constitute an ab initio method for theoretical study of this gas. As an example, I show an exploratory calculation of the critical temperature separating the normal and superfluid phases. Next, I outline how effective field theory enables one to study the low temperature properties of the gas beyond superfluid hydrodynamics. It turns out that this system possesses a great deal of symmetry which tightly constrains the form of next-to-leading order behavior.