Nanocrystals of diluted magnetic semiconductors: Model for magnetic polaron

Abstract

We present a simple model for the magnetic polaron associated with an electron-hole pair in a semimagnetic semiconductor quantum dot. An exactly soluble Hamiltonian based on the effective-mass approximation is used to calculate the equilibrium properties. The polaron binding energy decreases with increasing temperature or magnetic field. Low-temperature magnetization and luminescence polarization show rapid saturation with magnetic field. Strong light-induced enhancement of magnetization is predicted.