EFFECT OF SPIN-GLASS ORDER ON MAGNETIC POLARONS IN SEMIMAGNETIC SEMICONDUCTORS

A theory accounting for the specific features of magnetic polarons (MP 's) in the presence of spin-glass order is presented. We derive and so lve self-consistent equations for (i) the polaron magnetization, (ii) the thermodynamically averaged carrier spin, and (iii) the spin-glass order parameter. The temperature dependence of these quantities is ana lyzed in detail. The modification of the spin-glass phase due to the p resence of the exchange field of the carrier inside the magnetic polar on volume is investigated. The onset of spin-glass order leads to a pl ateaulike flattening in the temperature dependence of the MP energy at low temperatures. It is found that solutions of spin-glass equations are needed to optimally fit the experimental data of the;temperature d ependence of the exciton magnetic polaron energy in (Cd,Mn)Te. Moreove r, the dynamical aspects of the MP formation are discussed. Our model predicts qualitatively different temperature dependences of the MP for mation time in different dynamical scenarios.