Charge and Magnetization Inhomogeneities in Diluted Magnetic Semiconductors

TL;DR

This paper predicts that diluted magnetic semiconductors can develop stripe-like inhomogeneities in magnetization and charge distribution below a certain temperature, driven by strong coupling between charge and magnetic properties.

Contribution

It introduces a theoretical model showing inhomogeneous magnetization and charge modulations in diluted magnetic semiconductors below a characteristic temperature T*.

Findings

Stripe-like magnetization modulations predicted below T*

Amplitude and wavelength of modulations increase as temperature decreases

Charged layers form in domain walls due to charge-magnetization coupling

Abstract

It is predicted that III-V diluted magnetic semiconductors can exhibit stripe-like modulations of magnetization and carrier concentration. This inhomogeneity results from the strong dependence of the magnetization on the carrier concentration. Within Landau theory, a characteristic temperature T* below the Curie temperature is found so that below T* the equilibrium magnetization shows modulations, which are strongly anharmonic. Wavelength and amplitude of the modulation rise for decreasing temperature, starting from zero at T*. Above T* the equilibrium state is homogeneous, but the coupling between charge and magnetization leads to the appearance of an electrically charged layer in domain walls.