Phase diagram of vortices in double-layer quantum Hall systems.

Abstract

We consider the finite-temperature phase diagram of a classical effective model of charged collective vortex excitations in incompressible states with spontaneous interlayer coherence in double layer quantum Hall systems. The phase diagram exhibits surprisingly rich structure, including a Kosterlitz-Thouless transition at high core energy, crystal phases at low core energy, and a variety of transitions between the phases. Our results suggest that alternatives to the expected Kosterlitz-Thouless transition are possible in double layer quantum Hall systems.