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Current and strain-induced spin polarization in InGaN/GaN superlattices
H J Chang1, T W Chen, J W Chen
1Department of Physics, National Taiwan University, Taipei 106, Taiwan.
Physical Review Letters
|May 16, 2007
Summary
This study demonstrates lateral current-induced spin polarization in InGaN/GaN superlattices, showcasing the spin Hall effect. Internal strains were found to strongly manipulate this spin polarization, offering new methods for generating spin-polarized currents.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Spin Hall effect generates spin currents from charge currents.
- Indium Gallium Nitride/Gallium Nitride (InGaN/GaN) superlattices are promising for spintronic applications.
Purpose of the Study:
- To investigate lateral current-induced spin polarization in InGaN/GaN superlattices.
- To explore the influence of internal strains on the spin Hall effect.
- To develop a theoretical understanding of strain-induced spin polarization.
Main Methods:
- Experimental observation of lateral current-induced spin polarization.
- Analysis of spin polarization reversal with current reversal.
- Investigation of strain effects on spin Hall effect.
- Theoretical modeling of strain-induced spin polarization.
Main Results:
- Demonstrated lateral current-induced spin polarization in InGaN/GaN superlattices without magnetic fields.
- Observed clear signatures of the spin Hall effect, including sign changes with current reversal and opposite signs at edges.
- Discovered strong manipulation of the spin Hall effect by internal strains.
- Developed theoretical framework explaining strain-induced spin polarization.
Conclusions:
- InGaN/GaN superlattices exhibit significant spin Hall effect.
- Internal strains provide a powerful mechanism for controlling spin polarization.
- This work offers a novel pathway for generating spin-polarized currents.
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