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Published on: August 2, 2019
100% spin accumulation in non-half-metallic ferromagnet-semiconductor junctions.
A G Petukhov1, J Niggemann, V N Smelyanskiy
1Physics Department, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA.
Summary
Achieve 100% spin polarization in non-magnetic semiconductors. This complete spin accumulation occurs in ferromagnet-semiconductor junctions without needing half-metallic contacts, even with moderate selectivity.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Semiconductor Spintronics
Background:
- Spin polarization is crucial for spintronics applications.
- Achieving high spin polarization in non-magnetic semiconductors is challenging.
- Current methods often rely on half-metallic ferromagnetic contacts.
Purpose of the Study:
- To demonstrate 100% spin polarization of electron density in non-magnetic semiconductors.
- To investigate the conditions for achieving complete spin accumulation.
- To establish a theoretical framework relating current spin polarization to electron density spin polarization.
Main Methods:
- Theoretical derivation of a general equation for spin polarization.
- Analysis of ferromagnet-semiconductor (FM-n(+)-n) junctions.
- Modeling electron transport and spin dynamics in heavily doped semiconductor layers.
Main Results:
- 100% spin polarization of electron density is achievable in non-magnetic semiconductors.
- Complete spin accumulation does not necessitate half-metallic ferromagnetic contacts.
- The effect is realized in FM-n(+)-n junctions with moderate spin selectivity.
Conclusions:
- Complete spin polarization can be achieved near the n(+)-n interface.
- This occurs when spin-up electron concentration approaches zero while their diffusion current remains finite.
- The findings open new avenues for spintronic device design using non-magnetic materials.
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