• DOI:10.1103/PhysRevB.102.094517
• Corpus ID: 220364834

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

@article{Volkov2020SignaturesOA,
  title={Signatures of a long-range spin-triplet component in an Andreev interferometer},
  author={Anatoly F. Volkov},
  journal={Physical Review B},
  year={2020},
  volume={102}
}

• A. Volkov
• Published 6 July 2020
• Materials Science, Mathematics
• Physical Review B

We analyze the Josephson ${I}_{J}$ and dissipative ${I}_{\text{dis}}$ 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 ${\mathrm{SF}}_{l}\text{\ensuremath{-}}\mathrm{F}\text{\ensuremath{-}}{\mathrm{F}}_{r}\mathrm{S}$ circuit and perpendicular to it a N-F-N circuit, where S, ${\mathrm{F}}_{l,r}$ are superconductors and weak ferromagnets with noncollinear magnetizations ${\mathbf{M}}_{l,r}$, 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 ${I}_{J}={I}_{c}(\ensuremath{\alpha},\ensuremath{\beta})sin\ensuremath{\varphi}$ and ${I}_{\text{dis}}={I}_{V}(\ensuremath{\alpha},\ensuremath{\beta})cos\ensuremath{\varphi}$. In particular, the critical Josephson current in a long Josephson junction (JJ) is ${I}_{c}(\ensuremath{\alpha},\ensuremath{\beta})={I}_{c0}\ensuremath{\chi}(\ensuremath{\alpha},\ensuremath{\beta})$, where the function $\ensuremath{\chi}(\ensuremath{\alpha},\ensuremath{\beta})$ is a function of angles ${(\ensuremath{\alpha},\ensuremath{\beta})}_{l,r}$ that characterize the orientations of ${\mathbf{M}}_{l,r}$. The oscillating part of the dissipative current ${I}_{\text{osc}}(V)=\ensuremath{\chi}(\ensuremath{\alpha},\ensuremath{\beta})cos\ensuremath{\varphi}{I}_{V0}(V)$ in the N-F/n-N circuit depends on the angles ${(\ensuremath{\alpha},\ensuremath{\beta})}_{l,r}$ in the same way as the critical Josephson current ${I}_{c}(\ensuremath{\alpha},\ensuremath{\beta})$ but can be much greater than the ${I}_{c}(\ensuremath{\alpha},\ensuremath{\beta})$. At some angles the current ${I}_{c}(\ensuremath{\alpha},\ensuremath{\beta})$ changes sign. We briefly discuss a relation between the negative current ${I}_{c}(\ensuremath{\alpha},\ensuremath{\beta})$ 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.