Detection of nonequilibrium phonons by the exciton luminescence in CdMnTe-based quantum wells

Exciton luminescence of semimagnetic semiconductor quantum well structures based on Cd1-xMnxTe is used for the first time as spectrometer for acoustic phonons in the subterahertz region. The principle of such a phonon spectro meter is based on the changes of the giant Zeeman splitting of the exciton states in the presence of nonequilibrium phonons which by means of direct s pin-phonon transitions raise the temperature of the spin system of Mn ions. The detection of the well known phonon spectrum of losses at a crystal/hel ium interface is demonstrated. (C) 1999 Elsevier Science B.V. All rights re served.