First observation and experimental proof of free magnetic polaron formation in CdTe/(Cd, Mn)Te quantum wells

We report the first experimental observation of free magnetic polarons in diluted magnetic semiconductor quantum wells. CdTe/Cd 0.78Mn0.22Te multiple quantum well structures with quantum well widths up to 100 A were investigated by reflection, photoluminescence and photoluminescence excitation spectroscopy at low temperatures and in magnetic fields. Free and bound magnetic polaron energies were determined by the suppression of polaron formation with increasing temperature and in external magnetic fields.