Signatures of odd-frequency correlations in the Josephson current of superconductor/ferromagnet hybrid junctions

Caroline Richard (1) , Alexandre I. Buzdin (2) , Manuel Houzet (1) , Julia S. Meyer (1)

1 GT - Laboratory of Quantum Theory
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine

Contacting a bilayer ferromagnet with a singlet even-frequency superconductor allows for the realization of an effective triplet odd-frequency superconductor. In this work, we investigate the Josephson effect between superconductors with different symmetries (e.g. odd- versus even-frequency). In particular, we study the supercurrent flowing between two triplet odd-frequency superconducting leads through a weak singlet even-frequency superconductor. We show that the peculiar temperature dependence of the critical current below the superconducting transition of the weak superconductor is a signature of the competition between odd/odd-frequency and odd/even-frequency Josephson couplings.

Mots clés: Tunneling phenomena; Magnetic properties of interfaces (multilayers superlattices heterostructures); Pairing symmetries (other than s-wave); Andreev reflection; SN and SNS junctions; Josephson effects; Proximity effects

Domaines: Supraconductivité [cond-mat.supr-con]

Caroline Richard, Alexandre I. Buzdin, Manuel Houzet, Julia S. Meyer. Signatures of odd-frequency correlations in the Josephson current of superconductor/ferromagnet hybrid junctions. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2015, 92 (9), pp.094509 (1-8). ⟨10.1103/PhysRevB.92.094509⟩. ⟨hal-01216352⟩