Two-dimensional exciton magnetic polaron in semimagnetic quantum wells

• Published in: Surface science Vol. 263; no. 1; pp. 485 - 490
• Main Authors: Yakovlev, D.R., Uraltsev, I.N., Ossau, W., Landwehr, G., Bicknell-Tassius, R.N., Waag, A., Schmeusser, S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 19.02.1992; Amsterdam Elsevier Science; New York, NY
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Surface and interface electron states
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(92)90394-L

We report the systematic investigation of two-dimensional magnetic polarons formed from excitons localized in very thin nonmagnetic CdTe quantum wells confined by Cd 1− x Mn x Te semimagnetic barriers. Analysis of the Stokes shift of the exciton luminescence peak under resonance excitation, which is a dramatically decreasing function of temperature and magnetic field, allows us to determine the magnetic polaron energy. The polaron energy measured as a function of quantum well width is found to be 25 meV in 6 Å thick quantum wells and to vanish in wells thicker than 30 Å. Values of the polaron luminescence linewidth appear to be close to the magnetic polaron energies and to follow the polaron energy dependences on the well width or magnetic fields. This fact indicates that a rather small number of the Mn 2+ spins are involved in the magnetic polaron formation.