Theory of Tunneling in the Exciton Condensate of Bilayer Quantum Hall Systems

TL;DR

This paper develops a theory for interlayer tunneling in bilayer quantum Hall systems with exciton condensates, predicting enhanced conductance peaks near zero bias that align with experimental observations, emphasizing the role of interlayer coherence.

Contribution

It introduces a new theoretical framework for tunneling in exciton condensates that accounts for strong interlayer correlations, differing from traditional Josephson effect explanations.

Findings

Predicted finite, enhanced tunneling conductance peaks near zero bias.

Calculated conductance peak height as a function of interlayer distance.

Results agree well with experimental data.

Abstract

We develop a theory of interlayer tunneling in the exciton condensate of bilayer quantum Hall systems, which predicts strongly enhanced, but finite, tunneling conductance peaks near zero bias even at zero temperature. It is emphasized that, though this strongly enhanced tunneling originates from spontaneous interlayer phase coherence, it is fundamentally not the Josephson effect. Because of strong interlayer correlation, the bilayer system behaves as a single system so that conventional tunneling theories treating two layers as independent systems are not applicable. Based on our theory, we compute the height of conductance peak as a function of interlayer distance, which is in good agreement with experiment.