Minigap suppression in S(N/F)S junctions
Date/Time: 17:30 24-Jun-2020
Abstract:
We consider long diffusive S(N/F)S junctions where the normal region N is in contact with a ferromagnet or ferromagnetic insulator along the junction (i.e. along the current direction). Exploiting the small thickness of the NF bilayer, we construct effective 1d Usadel equations describing such junctions in the case of transparent NF interfaces. In addition to the well-anticipated effective exchange-field term, a depairing term ~sin(2θ) emerges. We attribute it to the inherent inhomogeneity of the weak link in the transverse direction. The depairing term leads to the suppression of the minigap in the spin-resolved spectra, which distinguishes such hybrid S(N/F)S systems from regular SFS systems where only spin-splitting of the minigap would occur. We apply the developed theory to a number of setups and geometries and compare it to numerical solutions of the initial 2d problem and experimental results on S(N/F)S junctions.
Video
Authors
Ioselevich Pavel A
(Presenter)
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