Vanishing Hall Resistance at High Magnetic Field in a Double Layer Two-Dimensional Electron System

TL;DR

This paper reports the observation of vanishing Hall resistance in a double layer 2D electron system at high magnetic fields, supporting the existence of an excitonic superfluid state at total filling factor one.

Contribution

It provides experimental evidence for the vanishing Hall resistance and superfluid behavior in a double layer 2D electron system at high magnetic fields.

Findings

Vanishing Hall resistance when currents are oppositely directed in layers.

Supports the excitonic superfluid ground state at ν_{tot}=1.

Quantized Hall effect observed with parallel currents.

Abstract

At total Landau level filling factor $\nu_{tot}=1$ a double layer two-dimensional electron system with small interlayer separation supports a collective state possessing spontaneous interlayer phase coherence. This state exhibits the quantized Hall effect when equal electrical currents flow in parallel through the two layers. In contrast, if the currents in the two layers are equal, but oppositely directed, both the longitudinal and Hall resistances of each layer vanish in the low temperature limit. This finding supports the prediction that the ground state at $\nu_{tot}=1$ is an excitonic superfluid.