Magnetic-field-induced crossover from the inverse Faraday effect to the optical orientation in EuTe
Abstract
A time-resolved optical pump-probe technique has been applied for studying the ultrafast dynamics in the magnetic semiconductor EuTe near the absorption band gap. We show that application of external magnetic field up to 6 T results in crossover from the inverse Faraday effect taking place on the femtosecond time scale to the optical orientation phenomenon with an evolution in the picosecond time domain. We propose a model which includes both these processes, possessing different spectral and temporal properties. The circularly polarized optical pumping induces the electronic transition 4 f 7 5 d 0 → 4 f 6 5 d 1 forming the absorption band gap in EuTe. The observed crossover is related to a strong magnetic-field shift of the band gap in EuTe at low temperatures. It was found that manipulation of spin states on intrinsic defect levels takes place on a time scale of 19 ps in the applied magnetic field of 6 T.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- May 2018
- DOI:
- 10.1063/1.5027473
- arXiv:
- arXiv:1803.02633
- Bibcode:
- 2018JAP...123s3102P
- Keywords:
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- Condensed Matter - Materials Science
- E-Print:
- 11 pages, 4 figures