A1 Journal article (refereed)
Charge transport through spin-polarized tunnel junction between two spin-split superconductors (2019)

Rouco, M., Chakraborty, S., Aikebaier, F., Golovach, V. N., Strambini, E., Moodera, J. S., Giazotto, F., Heikkilä, T. T., & Bergeret, F. S. (2019). Charge transport through spin-polarized tunnel junction between two spin-split superconductors. Physical Review B, 100(18), Article 184501. https://doi.org/10.1103/PhysRevB.100.184501

JYU authors or editors

Publication details

All authors or editors: Rouco, Mikel; Chakraborty, Subrata; Aikebaier, Faluke; Golovach, Vitaly N.; Strambini, Elia; Moodera, Jagadeesh S.; Giazotto, Francesco; Heikkilä, Tero T.; Bergeret, F. Sebastian

Journal or series: Physical Review B

ISSN: 2469-9950

eISSN: 2469-9969

Publication year: 2019

Volume: 100

Issue number: 18

Article number: 184501

Publisher: American Physical Society

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevB.100.184501

Publication open access: Not open

Publication channel open access: 

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/66321

Web address of parallel published publication (pre-print): https://arxiv.org/abs/1906.09079

Abstract

We investigate transport properties of junctions between two spin-split superconductors linked by a spin-polarized tunneling barrier. The spin-splitting fields in the superconductors (S) are induced by adjacent ferromagnetic insulating (FI) layers with arbitrary magnetization. The aim of this study is twofold. On the one hand, we present a theoretical framework based on the quasiclassical Green's functions to calculate the Josephson and quasiparticle current through the junctions in terms of the different parameters characterizing it. Our theory predicts qualitative new results for the tunneling differential conductance, dI/dV, when the spin-splitting fields of the two superconductors are noncollinear. We also discuss how junctions based on FI/S can be used to realize anomalous Josephson junctions with a constant geometric phase shift in the current-phase relation. As a result, they may exhibit spontaneous triplet supercurrents in the absence of a phase difference between the S electrodes. On the other hand, we show results of planar tunneling spectroscopy of a EuS/Al/AlOx/EuS/Al junction and use our theoretical model to reproduce the obtained dI/dV curves. Comparison between theory and experiment reveals information about the intrinsic parameters of the junction, such as the size of the superconducting order parameter, spin-splitting fields and spin relaxation, and also about properties of the two EuS films, such as their morphology, domain structure, and magnetic anisotropy.

Keywords: superconductors; superconductivity

Free keywords: Josephson effect; proximity effect; superconductivity

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Ministry reporting: Yes

Reporting Year: 2019

JUFO rating: 2