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Persistent sourcing of coherent spins for multifunctional semiconductor spintronics
I Malajovich1, J J Berry, N Samarth
1Department of Physics, University of California, Santa Barbara 93106, USA.
Nature
|July 19, 2001
Summary
Researchers discovered a persistent spin-conduction mode in biased semiconductor heterostructures, significantly extending spin-transfer duration. This breakthrough enhances prospects for advanced spintronic devices with electrical or magnetic field control.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Electronics
Background:
- Semiconductors exhibit spin-coherent transport, crucial for spintronics.
- Spin injection into semiconductors is challenging, often relying on magnetic semiconductors.
- Previous optical methods yielded short spin transfer durations across interfaces.
Purpose of the Study:
- To investigate a 'persistent' spin-conduction mode in biased semiconductor heterostructures.
- To enhance coherent spin transfer across semiconductor interfaces.
- To explore new avenues for spintronic device development.
Main Methods:
- Utilized biased semiconductor heterostructures.
- Employed time-resolved Kerr spectroscopy.
- Investigated spin-coherent injection through parallel channels.
Main Results:
- Demonstrated a persistent spin-conduction mode lasting significantly longer than in unbiased structures.
- Observed up to a 500% increase in spin-coherent injection in biased structures.
- Achieved up to a 4,000% increase with p-n junctions for built-in bias.
Conclusions:
- Biased semiconductor heterostructures enable persistent spin-coherent transport.
- This method offers a substantial improvement over existing spin injection techniques.
- Paves the way for multifunctional spintronic devices controlled by electrical or magnetic fields.
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