2004/06/30 by R. Mélin · 1 citation
Materials Science · Physics and Astronomy · #Computer science #Condensed matter physics #Current (fluid) #Data mining #Ferromagnetism #Magnetic Properties and Applications #Phase (matter) #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum decoherence #Quantum mechanics #Relation (database) #Thermodynamics #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1209/epl/i2004-10303-6
published as Europhys. Lett. 69, 121 (2005) · 7 pages, 3 figures, article rewritten
arxiv created 2004/08/27 · openalex publication_date 2004/12/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We propose a theoretical description of the sin (2φ) current-phase relation in SFS junctions at the 0-π crossover obtained in recent experiments by Sellier et al. ( Phys. Rev. Lett. , 92 (2004) 257005, cond-mat/0406236), where it was suggested that a strong decoherence in the magnetic alloy can explain the magnitude of the residual supercurrent at the 0-π crossover. To describe the interplay between decoherence and elastic scattering in the ferromagnet, we use an analogy with crossed Andreev reflection in the presence of disorder. The supercurrent as a function of the length R of the ferromagnet decays exponentially over a length ξ, larger than the elastic scattering length l d in the absence of decoherence, and smaller than the coherence length l φ in the absence of elastic scattering on impurities. The best fit leads to ξ ≃ ξ h (diff) /3, where ξ h (diff) is the exchange length of the diffusive system without decoherence (also equal to ξ in the absence of decoherence). The fit of experiments works well for the amplitude of both the sin φ and sin (2φ) harmonics.