Abstract
We use a novel optical probe of magnetization to explore the evolution of carrier spin scattering and magnetic dynamics in quantum-confined geometries. II-VI magnetic heterostructures are studied using femtosecond Faraday rotation and exhibit both carrier phase- (approx. 1 ps) and spin-scattering (approx. 6 ps) in concert with a field-tunable terahertz quantum-beating of the total carrier spin. Spin-flip processes experienced by photoexcited carriers as they tunnel through nanometer-thick magnetic barriers produce a magnetic perturbation strongly sensitive to the initial magnetic state and the spin-orientation of the pumped carriers. Once these carriers have recombined (approx. 70 ps), the magnetic ions relax through completely different channels of significantly slower decay rate (100 ps - 10 ns). The relaxation characteristics are found to be substantially influenced by exchange coupling between adjacent magnetic ions at low temperatures (T < 13 K). These low-dimensional magnetic systems yield a rich array of spin phenomena untapped in traditional semiconductor heterostructures.
Original language | English (US) |
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Pages (from-to) | 429-434 |
Number of pages | 6 |
Journal | Materials Science Forum |
Volume | 182-184 |
DOIs | |
State | Published - 1995 |
Event | Proceedings of the 4th International Workshop on Semimagnetic (Diluted Magnetic) Semiconductors - Linz, Austria Duration: Sep 26 1994 → Sep 28 1994 |
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering