Spin ordering: two different scenarios for the single and double layer structures in the fractional and integer quantum Hall effect regimes

TL;DR

This paper explores the different spin transition scenarios in single and double layer quantum Hall systems at specific filling factors, analyzing phase transitions through conductivity measurements and domain structure evolution.

Contribution

It identifies two distinct transition scenarios in quantum Hall systems and offers a qualitative explanation for one, highlighting differences between single and double layer structures.

Findings

Two different spin transition scenarios are observed.

A qualitative domain evolution model explains one scenario.

The origin of the second scenario remains unclear.

Abstract

We investigate the ground state competition at the transition from the spin unpolarized to spin ordered phase at filling factor $\nu=2/3$ in single layer heterostructure and at $\nu=2$ in double layer quantum well. To trace the quantum Hall phase we use the minimum in the dissipative conductivity $\sigma_{xx}$. We observe two different transition scenarios in two investigated situations. For one of them we propose a qualitative explanation, based on the domain structure evolution in the vicinity of the transition point. The origin for the second scenario, corresponding to the experimental situation at $\nu=2$ in double layer 2DES, still remains unclear.