Critical Transport in Cold Atomic Fermi Gas

Abstract

In this paper, we will analyze the properties of critical transport in a 2-component unitary Fermi gas. This system is of particular interest because there is active experimental research on the system with cold atomic gases. There are several concepts we would like to explore. First, we will show how the thermal conductivity, driven by a temperature gradient near the super fluid critical point, diverges. Then, we extend the argument to the system with unequal densities of up- and down-spin fermions. In order to do this, we extend upon the F model proposed by Halperin et al [1] to include the spin density as an additional parameter. Using the proposed model, we assess spin Seebeck and Peltier effects at phase boundary to confirm that there is an eigenmode in current, in which divergence disappears. Finally, we find that one needs to break the linear approximation in order to observe a different behavior at the tricritical point.