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Multi-Terminal Spin Valve on Channels with Spin-Momentum Locking
Shehrin Sayed1, Seokmin Hong1, Supriyo Datta1
1School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
Scientific Reports
|October 22, 2016
Summary
Spin-momentum locking in materials like topological insulators can alter spin valve resistance. This effect, dependent on spin flow direction, is observable only in multi-terminal measurements, unlike simpler two-terminal setups.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Charge current in spin-momentum locked channels induces measurable spin voltage.
- Onsager reciprocity is a key principle in understanding transport phenomena.
Purpose of the Study:
- To predict the behavior of spin valve resistance in the presence of spin-momentum locking.
- To differentiate the effects observable in multi-terminal versus two-terminal measurements.
Main Methods:
- Theoretical prediction using Onsager reciprocity arguments.
- Numerical calculations based on a semiclassical model.
Main Results:
- Spin valve resistance can be greater or lesser than in channels without spin-orbit coupling, depending on spin flow direction relative to spin-momentum locking.
- This signature is only observable in multi-terminal measurements.
- Two-terminal measurements show a single anti-parallel resistance, larger than parallel resistance.
Conclusions:
- Spin-momentum locking offers a novel way to manipulate spin valve resistance.
- Multi-terminal measurements are crucial for observing unique spintronic phenomena.
- The findings provide insight into the physics of spin transport in advanced materials.
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