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Spin-transfer and exchange torques in ferromagnetic superconductors
Jacob Linder1, Arne Brataas, Zahra Shomali
1Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
Physical Review Letters
|February 2, 2013
Summary
Superconducting correlations create novel spin-transfer torques in ferromagnetic superconductors. These torques, influenced by particle-hole interference and Andreev states, depend on the superconducting order parameter
Area of Science:
- Condensed matter physics
- Spintronics
- Superconductivity
Background:
- Ferromagnetic superconductors combine magnetic and superconducting properties.
- Spin-transfer torques are crucial for manipulating magnetization in spintronic devices.
Purpose of the Study:
- To investigate the influence of superconducting correlations on spin-transfer torques in ferromagnetic superconductors.
- To identify novel torque mechanisms arising from superconductivity.
Main Methods:
- Theoretical analysis of spin-transfer torques in ferromagnetic superconductor heterostructures.
- Consideration of particle-hole interference effects.
- Modeling of Andreev states mediating exchange interactions.
Main Results:
- A novel torque mechanism due to particle-hole interference, dependent on the U(1) phase of the superconducting order parameter.
- An equilibrium exchange torque between ferromagnetic superconductors mediated by Andreev states.
- Sensitivity of the equilibrium torque to spin-resolved phase differences and external phase shifts.
Conclusions:
- Superconducting correlations introduce unique torque phenomena in ferromagnetic superconductors.
- The U(1) phase of the superconducting order parameter plays a critical role in generating these torques.
- Exploiting these phase-dependent torques offers new avenues for magnetic control in superconducting spintronic devices.
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