Correlations, compressibility, and capacitance in double-quantum-well systems in the quantum Hall regime

TL;DR

This paper investigates how electronic correlations in double-layer quantum Hall systems influence charge distribution and capacitance, using Hartree-Fock calculations to explore inter-layer phase coherence and potential experimental probing methods.

Contribution

It introduces a theoretical framework to analyze inter-layer correlations and capacitance in double-quantum-well systems within the quantum Hall regime, highlighting the role of spontaneous phase coherence.

Findings

Correlations affect charge partitioning between layers.

Capacitance reflects inter-layer correlations.

Spontaneous phase coherence can be studied via capacitive coupling.

Abstract

In the quantum Hall regime, electronic correlations in double-layer two-dimensional electron systems are strong because the kinetic energy is quenched by Landau quantization. In this article we point out that these correlations are reflected in the way the partitioning of charge between the two-layers responds to a bias potential. We report on illustrative calculations based on an unrestricted Hartree-Fock approximation which allows for spontaneous inter-layer phase coherence. The possibility of studying inter-layer correlations by capacitive coupling to separately contacted two-dimensional layers is discussed in detail.