Critical Resistance of the Quantum Hall Ferromagnet in AlAs 2D Electrons

TL;DR

This paper investigates the magnetic phase transition in AlAs 2D electrons within the quantum Hall regime, identifying critical behavior and how the Curie temperature varies with carrier density.

Contribution

It provides the first measurement of the Curie temperature in a quantum Hall ferromagnet in AlAs 2D electrons and shows its dependence on carrier density.

Findings

Resistance spikes indicate magnetic domain wall scattering.

Curie temperature increases with carrier density.

Critical behavior observed in spike width and amplitude.

Abstract

Magnetic transitions in AlAs two-dimensional electrons give rise to sharp resistance spikes within the quantum Hall effect. Such spikes are likely caused by carrier scattering at magnetic domain walls below the Curie temperature. We report a critical behavior in the temperature dependence of the spike width and amplitude, from which we deduce the Curie temperature of the quantum Hall ferromagnet. Our data also reveal that the Curie temperature increases monotonically with carrier density.