Phase Transitions of S=1 Spinor Condensates in an Optical Lattice

TL;DR

This paper explores the complex phase transitions in S=1 spinor condensates within optical lattices, revealing novel topological phenomena and transition behaviors influenced by magnetic anisotropy and spin parity.

Contribution

It introduces the concept of topological binding of vorticity to nematic disclinations, leading to new types of Kosterlitz-Thouless transitions in spinor condensates.

Findings

Identification of Kosterlitz-Thouless-like transitions with tunable superfluid stiffness

Discovery of a cascaded Kosterlitz-Thouless transition with two divergent length scales

Demonstration that the thermal phase transition depends on the parity of the spin S

Abstract

We study the phase diagram of spin-one polar condensates in a two dimensional optical lattice with magnetic anisotropy. We show that the topological binding of vorticity to nematic disclinations allows for a rich variety of phase transitions. These include Kosterlitz-Thouless-like transitions with a superfluid stiffness jump that can be experimentally tuned to take a continuous set of values, and a new cascaded Kosterlitz-Thouless transition, characterized by two divergent length scales. For higher integer spin bosons S, the thermal phase transition out of the planar polar phase is strongly affected by the parity of S.