Eur. Phys. J. B (2012) 85: 289
https://doi.org/10.1140/epjb/e2012-30354-1

Regular Article

Electronic and optical spectra in a diluted magnetic semiconductor multilayer

¹ Department of Physics, Payame Noor University, P.O. Box 19395-3697, Tehran, Iran
² Department of Physics, Simon Fraser University, V5A 1S6 Burnaby, British Columbia, Canada

^a e-mail: a-saffar@tpnu.ac.ir

Received: 30 April 2012
Received in final form: 27 June 2012
Published online: 20 August 2012

Abstract

The effects of random distribution of magnetic impurities with concentration x in a semiconductor alloy multilayer at a paramagnetic temperature are investigated by means of coherent potential approximation and tight-binding model. The change in the electronic states and the optical absorption spectrum with x is calculated for weak and strong exchange interactions between carrier spins and localized spin moments on magnetic ions. We find that the density of states and optical absorption are strongly layer-dependent due to the quantum size effects. The electronic and optical spectra are broadened due to the spin fluctuations of magnetic ions and in the case of strong exchange interaction, an energy gap appears in both spectra. Furthermore, the interior layers show higher contribution in the optical absorption of the system. The results can be helpful for magneto-optical devices at a paramagnetic temperature.