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Dynamic nuclear polarization by electrical spin injection in ferromagnet-semiconductor heterostructures
J Strand1, B D Schultz, A F Isakovic
1School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Physical Review Letters
|August 9, 2003
Summary
This study demonstrates electrical spin injection from iron (Fe) into aluminum gallium arsenide (AlxGa1-xAs) quantum wells. A model explains observed hysteresis by considering magnetic anisotropy, spin relaxation, and nuclear spin polarization.
Area of Science:
- Spintronics
- Condensed Matter Physics
- Materials Science
Background:
- Electrical spin injection is crucial for spintronic devices.
- Semiconductor heterostructures enable control over electron spin properties.
Purpose of the Study:
- To demonstrate and analyze electrical spin injection from ferromagnetic iron into AlxGa1-xAs quantum wells.
- To model the observed hysteresis in spin injection signals.
Main Methods:
- Electrical spin injection measurements in small in-plane magnetic fields.
- Utilizing a model incorporating magnetocrystalline anisotropy, spin relaxation, and dynamic nuclear spin polarization.
Main Results:
- Successful demonstration of electrical spin injection from Fe into AlxGa1-xAs quantum wells.
- Observed spin injection signal is sensitive to the internal magnetic field, which is current-dependent.
- Hysteresis in the spin injection signal is accurately reproduced by the developed model.
Conclusions:
- The study validates electrical spin injection in Fe/AlxGa1-xAs heterostructures.
- The model provides insights into the underlying physical mechanisms, including magnetic anisotropy and spin dynamics.
- This work contributes to the development of spin-based electronic devices.
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