2006/09/30 by G. Tkachov, Grygoriy Tkachov, Klaus Richter · 1 citation
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.75.134517
published as Phys. Rev. B 75, 134517 (2007) · 5 pages, 6 eps figures, new results added
arxiv created 2007/02/01 · openalex publication_date 2007/04/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose a model for resonant Josephson tunneling through quantum dots that accounts for Cooper pair-breaking processes in the superconducting leads caused by a magnetic field or spin-flip scattering. The pair-breaking effect on the critical supercurrent Ic and the Josephson current-phase relation I(\ensuremathφ) is largely due to the modification of the spectrum of Andreev bound states below the reduced (Abrikosov-Gorkov) quasiparticle gap. For a quantum dot formed in a quasi-one-dimensional channel, both Ic and I(\ensuremathφ) can show a significant magnetic-field dependence induced by pair breaking despite the suppression of the orbital magnetic-field effect in the channel. This case is relevant to recent experiments on quantum dot Josephson junctions in carbon nanotubes. Pair-breaking processes are taken into account via the relation between the Andreev scattering matrix and the quasiclassical Green functions of the superconductors in the Usadel limit.