Abstract:

In this talk I will discuss the critical properties of spin-1 polar spinor
condensates.  I will focus on two spatial dimensions at finite
temperatures.  Here, the topological binding of vorticity to nematic disclinations leads
to a rich phase diagram.  The physics is captured by a U(1) version of the
celebrated Ashkin-Teller model. In particular, I will discuss a novel
"cascaded" Kosterlitz-Thouless critical point, characterized by two
diverging scales and a non-universal superfluid stiffness jump. I will
also present Monte Carlo simulations to support these results.