English

Excess current in ferromagnet-superconductor structures with fully polarized triplet component

Superconductivity 2016-05-18 v2

Abstract

We study the II-VV characteristics of ST_{\text{T}}/n/N contacts, where ST_{\text{T}} is a BCS superconductor S with a built-in exchange field hh, n represents a normal metal wire, and N---a normal metal reservoir. The superconductor ST_{\text{T}} is separated from the n-wire by a spin filter which allows the passage of electrons with a certain spin direction so that only fully polarized triplet Cooper pairs penetrate into the n-wire. We show that both the subgap conductance σsg\sigma_{\text{sg}} and the excess current IexcI_{\text{exc}}, which occur in conventional S/n/N contacts due to Andreev reflection (AR), exist also in the considered system. In our case, they are caused by unconventional AR that is not accompanied by spin flip. The excess current IexcI_{\text{exc}} exists only if hh exceeds a certain magnitude hch_{\text{c}}. At h<hc{h < h_{\text{c}}} the excess current is converted into a deficit current IdefI_\text{{def}}. The dependencies of the differential conductance and the current IexcI_{\text{exc}} are presented as a function of voltage and hh.

Keywords

Cite

@article{arxiv.1603.06550,
  title  = {Excess current in ferromagnet-superconductor structures with fully polarized triplet component},
  author = {Andreas Moor and Anatoly F. Volkov and Konstantin B. Efetov},
  journal= {arXiv preprint arXiv:1603.06550},
  year   = {2016}
}

Comments

7+ pages, 5 figures

R2 v1 2026-06-22T13:15:32.966Z