Coulomb Drag of Edge Excitations in the Chern-Simons Theory of the Fractional Quantum Hall Effect

TL;DR

This paper investigates how long-range Coulomb interactions alter edge excitations in fractional quantum Hall systems, revealing correlated modes with unique dispersion and potential for parametric excitation within a Chern-Simons framework.

Contribution

It introduces a microscopic analysis of Coulomb drag effects on edge excitations, showing their correlated nature and nonlinear dispersion in the fractional quantum Hall regime.

Findings

Edge excitations become correlated across edges due to Coulomb interactions.

Dispersion law of excitations is nonlinear and depends on edge distance and current.

Long-range interactions significantly modify bulk density and current distributions.

Abstract

Long range Coulomb interaction between the edges of a Hall bar changes the nature of the gapless edge excitations. Instead of independent modes propagating in opposite directions on each edge as expected for a short range interaction one finds elementary excitations living simultaneously on both edges, i.e. composed of correlated density waves propagating in the same direction on opposite edges. We discuss the microscopic features of this Coulomb drag of excitations in the fractional quantum Hall regime within the framework of the bosonic Chern-Simons Landau-Ginzburg theory. The dispersion law of these novel excitations is non linear and depends on the distance between the edges as well as on the current that flows through the sample. The latter dependence indicates a possibility of parametric excitation of these modes. The bulk distributions of the density and currents of the edge excitations differ significantly for short and long range interactions.