Signatures of a long-range spin-triplet component in an Andreev interferometer

Article

关键词: JOSEPHSON-JUNCTION;    EXCHANGE FIELD;    METAL;    FERROMAGNET;    PHASE;    SUPERCONDUCTIVITY;    SUPERCURRENT;    CONDUCTANCE;    TRANSPORT;   

DOI  :  10.1103/PhysRevB.102.094517

来源: SCIE

【 摘 要 】

We analyze the Josephson I-J and dissipative I-dis currents in a magnetic Andreev interferometer in the presence of the long-range spin triplet component (LRSTC). The Andreev interferometer has a crosslike geometry and consists of a SFl-F-FrS circuit and perpendicular to it a N-F-N circuit, where S, F-l,F-r are superconductors and weak ferromagnets with noncollinear magnetizations M-l,M-r, and F is a ferromagnet with a high exchange energy. The ferromagnetic wire F can be replaced with a nonmagnetic wire n. In the limit of a weak proximity effect (PE), we obtain simple analytical expressions for the currents I-J = I-c (alpha , beta) sin phi and I-dis = I-v(alpha, beta) cos phi. In particular, the critical Josephson current in a long Josephson junction (JJ) is I-c(alpha,beta) = I-c0 chi(alpha, beta), where the function chi(alpha, beta) is a function of angles (alpha, beta)(l,r) that characterize the orientations of M-l,M- r. The oscillating part of the dissipative current I-ose(V) = chi(alpha, beta)cos phi I-v0(V) in the N-F/n-N circuit depends on the angles (alpha, beta)(l,r) in the same way as the critical Josephson current I-c(alpha, beta) but can be much greater than the I-c(alpha, beta). At some angles the current I-c(alpha, beta) changes sign. We briefly discuss a relation between the negative current I-c(alpha, beta) and paramagnetic response. We argue that the measurements of the conductance in the N-F/n-N circuit can be used as another complementary method to identify the LRSTC in S/F heterostructures.

【 授权许可】

Free