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Re-entrant superconductivity in Nb/Cu(1-x)Ni(x) bilayers

V. Zdravkov·A. Sidorenko·G. Obermeier·S. Gsell·M. Schreck·C. Müller·S. Horn·R. Tidecks·L. R. Tagirov
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Abstract

We report on the first observation of a pronounced re-entrant superconductivity phenomenon in superconductor/ferromagnetic layered systems. The results were obtained using a superconductor/ferromagnetic-alloy bilayer of Nb/Cu(1-x)Ni(x). The superconducting transition temperature T_{c} drops sharply with increasing thickness d_{CuNi} of the ferromagnetic layer, until complete suppression of superconductivity is observed at d_{CuNi}= 4 nm. Increasing the Cu(1-x)Ni(x) layer thickness further, superconductivity reappears at d_{CuNi}=13 nm. Our experiments give evidence for the pairing function oscillations associated with a realization of the quasi-one dimensional Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) like state in the ferromagnetic layer.

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V. Zdravkov, A. Sidorenko, G. Obermeier, S. Gsell, M. Schreck, C. Müller, S. Horn, R. Tidecks, L. R. Tagirov. 2006-02-19. Re-entrant superconductivity in Nb/Cu(1-x)Ni(x) bilayers. https://doi.org/10.1103/physrevlett.97.057004

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