Vortices, tunneling and deconfinement in bilayer excitonic quantum Hall superfluid

TL;DR

This paper investigates the role of vortices, instantons, and deconfinement in bilayer quantum Hall superfluids, developing an effective gauge theory to describe phase transitions and experimental implications.

Contribution

It introduces a gauge theory framework that incorporates vortices and instantons to analyze phase transitions in bilayer quantum Hall systems.

Findings

Identifies a continuous transition between confining and deconfined phases.

Shows the coupling of gauge fields to vortices affects phase behavior.

Discusses experimental signatures like tunneling conductance and layer imbalance.

Abstract

The physics of vortices, instantons and deconfinement is studied for layered superfluids in connection to bilayer quantum Hall systems at filling fraction nu=1. We develop an effective gauge theory taking into account both vortices and instantons induced by interlayer tunneling. The renormalization group flow of the gauge charge and the instanton fugacity shows that the coupling of the gauge field to vortex matter produces a continuous transition between the confining phase of free instantons and condensed vortices and a deconfined gapless superfluid where magnetic charges are bound into dipoles. The interlayer tunneling conductance and the layer imbalance induced inhomogeneous exciton condensate are discussed in connection to experiments.