Abstract
Optical pump-probe experiments were carried out in Cd1-xMnxTe/ZnTe multiple quantum wells to study the dynamics of the excitons and the exciton magnetic polarons in these materials. In the pump-probe spectra, three signals were detected. The main signal is negative and monitors the energy relaxation of the excitons created by the pump pulse. The two other pump-probe signals are positive and their intensity grows during the time when the excitons created by the pump pulse recombine. The low-energy positive pump-probe signal is found to track the average Mn spin polarization in the sample. Experiments performed with circular polarization show that long-range order is induced by a sufficiently intense pump beam. But in our samples, the spins of the excitons are found to be oriented mainly antiparallel to the long-range magnetization generated after the pump excitation. Furthermore, we found that, at high excitation densities, the excitons couple antiferromagnetically to the long-range 'background' magnetization of the Mn spins.
Original language | English |
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Pages (from-to) | 326-330 |
Number of pages | 5 |
Journal | Physica E: Low-Dimensional Systems and Nanostructures |
Volume | 10 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - 2001 May 1 |
Keywords
- CdMnTe
- Exciton magnetic polaron
- Pump probe
- Quantum wells
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics