Interlayer coupling in ferromagnetic semiconductor superlattices

TL;DR

This paper presents a mean-field theory for carrier-induced ferromagnetism in diluted magnetic semiconductors, accounting for spatial inhomogeneity, temperature, and exchange effects, demonstrated on MnGaAs/GaAs superlattices.

Contribution

It introduces an improved theoretical model that self-consistently includes inhomogeneity, temperature, and exchange interactions in ferromagnetic semiconductor superlattices.

Findings

Calculated electronic structure of MnGaAs/GaAs superlattice.

Demonstrated potential for designing semiconductor magnetoresistance systems.

Showed possibility of tuning magnetic properties through layer structure.

Abstract

We develop a mean-field theory of carrier-induced ferromagnetism in diluted magnetic semiconductors. Our approach represents an improvement over standard RKKY model allowing spatial inhomogeneity of the system, free-carrier spin polarization, finite temperature, and free-carrier exchange and correlation to be accounted for self-consistently. As an example, we calculate the electronic structure of a Mn$_x$Ga$_{1-x}$As/GaAs superlattice with alternating ferromagnetic and paramagnetic layers and demonstrate the possibility of semiconductor magnetoresistance systems with designed properties.