Termination of the spin-resolved integer quantum Hall effect

TL;DR

This study investigates how controlled disorder affects the termination of the spin-resolved integer quantum Hall effect in a GaAs/AlGaAs heterostructure, revealing a phase transition characterized by a rapid change in filling factor differences.

Contribution

It demonstrates that the termination of the spin-resolved quantum Hall effect can be described as a phase transition, with a universal scaling behavior across multiple Landau levels.

Findings

d7 The difference in filling factors d7 changes rapidly near a critical density.

d7 Scaling analysis shows collapse onto a single curve across Landau levels.

d7 Increasing Zeeman energy influences the phase transition.

Abstract

We report a magnetotransport study of the termination of the spin-resolved integer quantum Hall effect by controlled disorder in a gated GaAs/AlGaAs heterostructure. We have found that, for a given N^{th} Landau level, the difference in filling factors of a pair of spin-split resistivity peaks \delta\nu_{N}changes rapidly from one to zero near a critical density n_{c}. Scaling analysis shows that \delta\nu_{N} collapses onto a single curve independent of N when plotted against the parameter (n-n_{c})/n_{c} for five Landau levels. The effect of increasing the Zeeman energy is also examined by tilting the direction of magnetic field relative to the plane of the two-dimensional electron gas. Our experiment suggests that the termination of the spin-resolved quantum Hall effect is a phase transition.