Disorder and the quantum Hall ferromagnet

TL;DR

This paper explores how disorder affects the coupling between spinwaves and charge in quantum Hall ferromagnets, impacting their conductivity and magnetization properties.

Contribution

It reveals a novel coupling mechanism between spinwaves and disorder potential due to topological charge density in quantum Hall ferromagnets.

Findings

Disorder modifies the conductivity of quantum Hall ferromagnets.

Spinwave wavepackets induce oscillating dipole charges.

Coupling affects temperature dependence of magnetization.

Abstract

The distinguishing feature of the quantum Hall ferromagnet is the identity between the electrical and topological charge densities of a spin distortion. In addition to the wealth of physics associated with Skyrmionic excitations of the quantum Hall ferromagnet, this identification permits a rather curious coupling of spinwaves to the disorder potential. A wavepacket of spinwaves has an associated, oscillating dipole charge distribution, due to the non-linear form of the topological density. We investigate the way in which this coupling modifies the conductivity and temperature dependence of magnetization of the quantum Hall ferromagnet.