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Spin Josephson diode effect induced by higher-harmonic spin Josephson currents in a diffusive Josephson junction
1National Institute of Technology (KOSEN), Fukui College, Sabae, Fukui 916-8507, Japan.
Summary
This study reveals the spin Josephson diode effect (SJDE) in diffusive Josephson junctions. The interplay of spin-orbit interaction and exchange fields generates spin current asymmetry without external magnetic fields.
Area of Science:
- Condensed Matter Physics
- Spintronics
- Quantum Phenomena
Background:
- Josephson junctions are crucial for quantum electronics.
- Spin Josephson Diode Effect (SJDE) offers nonreciprocal spin transport.
- Rashba spin-orbit interaction and exchange fields are key in spintronic devices.
Purpose of the Study:
- To theoretically investigate the spin Josephson diode effect (SJDE).
- To explore SJDE in diffusive Josephson junctions with Rashba spin-orbit interaction and exchange fields.
- To understand the mechanism for nonreciprocal spin transport.
Main Methods:
- Utilizing the quasiclassical Green's function framework.
- Deriving analytical expressions for spin Josephson currents (first and second harmonic).
- Conducting numerical simulations to analyze efficiency and dependencies.
Main Results:
- The interplay of Rashba interaction and exchange field breaks symmetries, inducing a phase shift.
- This phase shift leads to intrinsic asymmetry in spin currents, enabling SJDE without external magnetic fields.
- Efficiency is sensitive to metal thickness and spin-orbit interaction strength.
Conclusions:
- The study demonstrates a mechanism for intrinsic nonreciprocal spin transport.
- SJDE can be achieved by tuning the interplay between spin-orbit interaction and exchange fields.
- This work provides insights into controlling spin currents in spintronic devices.
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