| 1. |
- Holmqvist, Cecilia, et al.
(author)
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Josephson current through a precessing spin
- 2009
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In: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 150
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Journal article (peer-reviewed)abstract
- A study of the dc Josephson current between two superconducting leads in thepresence of a precessing classical spin is presented. The precession gives rise to a time-dependenttunnel potential which not only creates different tunneling probabilities for spin-up and spin-down quasiparticles, but also introduces a time-dependent spin-flip term. In particular, westudy the effects of the spin-flip term alone on the Josephson current between two spin-singletsuperconductors as a function of precession frequency and junction transparency. The systemdisplays a steady-state solution although the magnitude and nature of the current is indeedaffected by the precession frequency of the classical spin.
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| 2. |
- Holmqvist, Cecilia, 1975, et al.
(author)
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Nonequilibrium effects in a Josephson junction coupled to a precessing spin
- 2011
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In: Physical Review B - Condensed Matter and Materials Physics. - 2469-9950 .- 2469-9969. ; 83:10
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Journal article (peer-reviewed)abstract
- We present a theoretical study of a Josephson junction consisting of two s-wave superconducting leads coupled over a classical spin. When an external magnetic field is applied, the classical spin will precess with the Larmor frequency. This magnetically active interface results in a time-dependent boundary condition with different tunneling amplitudes for spin-up and spin-down quasiparticles and where the precession produces spin-flip scattering processes. We show that as a result, the Andreev states develop sidebands and a nonequilibrium population which depend on the precession frequency and the angle between the classical spin and the external magnetic field. The Andreev states lead to a steady-state Josephson current whose current-phase relation could be used for characterizing the precessing spin. In addition to the charge transport, a magnetization current is also generated. This spin current is time dependent and its polarization axis rotates with the same precession frequency as the classical spin.
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| 3. |
- Teber, S., et al.
(author)
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Josephson current through a precessing classical spin
- 2009
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In: Physica. B, Condensed matter. - : Elsevier BV. - 0921-4526 .- 1873-2135. ; 404, s. 527-529
-
Journal article (peer-reviewed)abstract
- A study of the dc Josephson current between two superconducting leads in the presence of a precessingclassical spin is presented. The precession gives rise to a time-dependent tunnel potential which notonly implies different tunneling probabilities for spin-up and spin-down quasiparticles, but introducesalso a time-dependent spin-flip term. We provide an exact general analytic solution for the out-of-equilibrium steady-state permanent current between two spin-singlet superconductors as a functionof the superconducting phase difference, the precession frequency and for arbitrary junction transparency.As an application we focus on the effects of the spin-flip term alone and show that the magnitude andnature of the Josephson current are indeed strongly affected by the precession of the classical spin.
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