Tuning alloy disorder in diluted magnetic semiconductors in high fields to 89 T

TL;DR

This study investigates how alloy disorder in diluted magnetic semiconductors changes under extremely high magnetic fields up to 89 T, confirming a predicted increase in disorder at very large fields.

Contribution

The paper provides the first experimental measurement of alloy disorder behavior in DMS at magnetic fields up to 89 T, validating a model predicting increased disorder at very high fields.

Findings

Linewidth increases above 70 T, indicating increased alloy disorder.

Experimental data supports the simple model of alloy disorder at high fields.

Measurement extends understanding of magnetic field effects in DMS materials.

Abstract

Alloy disorder in II-VI diluted magnetic semiconductors (DMS) is typically reduced when the local magnetic spins align in an applied magnetic field. An important and untested expectation of current models of alloy disorder, however, is that alloy fluctuations in many DMS compounds should increase again in very large magnetic fields of order 100 tesla. Here we measure the disorder potential in a Zn$_{.70}$Cd$_{.22}$Mn$_{.08}$Se quantum well via the low temperature photoluminescence linewidth, using a new magnet system to 89 T. Above 70 T, the linewidth is observed to increase again, in accord with a simple model of alloy disorder.