EXCITON MAGNETIC POLARONS IN SHORT-PERIOD CDTE/CD1-XMNXTE SUPERLATTICES

The formation of magnetic polarons in short-period semimagnetic CdTe/Cd1-xMnxTe superlattices is studied by low-temperature cw and time-resolved photoluminescence and compared to the polaron formation in single quantum wells with the equivalent well width and manganese content. The dependence of the polaron energy on the superlattice period, i.e., quantum-well width, is identical to the dependence on well width in the corresponding single quantum wells. This implies that in the superlattice structures the polaron formation process does not lead to a spatial shift of the center of the hole wave function into the semimagnetic barrier. Temperature and magnetic-field-dependent measurements of the polaron energy reveal a more efficient polaron suppression in superlattices than in single quantum wells. This is attributed to the modification of the magnetic properties in the thin semimagnetic barrier layers of the superlattices. The different mechanisms of magnetic-field-induced polaron suppression in Faraday and Voigt geometries are discussed.