Speaker: Gautam Rupak (T-16, LANL)

Topics in dilute fermi and bose systems

At low temperatures and densities, there is a high degree of universality, in both fermi and bose systems. Effective field theory is an ideal tool in such situations for model independent calculations. First I will discuss a fermionic system composed of two particle species with different densities. Recent developments in cold atom traps and high density QCD has revived interests in the study of such an asymmetric fermionic system. I will argue that a mixed phase composed of normal and superfluid components is the energetically favored ground state. Second, I will discuss dilute bose systems where unusual properties of the three-body interactionin the presence of a shallow two-body bound state could lead to novel self bound liquids. The ability to tune two-body interaction essentially at will by means of a Feshbach resonance opens the possibility of manufacturing a new class of such quantum liquids. Further, I show that the contribution of the three-body interaction to thermodynamic functions mightbe the dominant one for systems with large two-body scattering length.