Composite-Fermion Analysis of the Double-Layer Fractional Quantum Hall System

TL;DR

This paper uses the composite-fermion approach to analyze how interlayer tunneling affects the double-layer fractional quantum Hall system at various filling factors, revealing that coupled Laughlin liquids can be viewed as composite fermions with modified interactions.

Contribution

It introduces a composite-fermion analysis directly applied to the electron-electron interaction in the double-layer fractional quantum Hall system, providing new insights into the effects of interlayer tunneling.

Findings

Quantum Hall regime widens as filling factor decreases from 1/3 to 1/5.

Coupled Laughlin liquids can be modeled as composite fermions with reduced interactions.

Comparison with numerical results supports the composite-fermion interpretation.

Abstract

Effect of interlayer tunneling in the double-layer fractional quantum Hall system at the total Landau level filling of $\nu=1/m$ ($m$: odd integer) is analyzed with the composite-fermion approach in which the flux attachment is directly applied to the electron-electron interaction. A comparison with a numerical result indicates that the vertically coupled Laughlin liquids may be regarded as a system of composite fermions with {\em reduced} interparticle interactions and {\em unchanged} interlayer tunneling, which makes the quantum-Hall regime, identified by a gap in the pseudospin-wave excitation mode, wider as $\nu$ becomes $1/3,1/5,\ldots$.