2015/06/30 by François Konschelle, Ilya V. Tokatly, F. Sebastián Bergeret · 2 citations
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.92.125443
published as Phys. Rev. B 92, 125443 (2015) · v1: article version of the preprints arXiv:1408.4533 and arXiv:1409.4563 in letter format, with far more results and details. v2: some typos and mistakes corrected, new presentation of the derivation at all temperature in the ballistic regime (section VI), including a new fig.2 to illustrate this section. v3: accepted version, with extra references
arxiv created 2015/10/05 · arxiv updated 2016/08/08
Due to the spin-orbit coupling (SOC) an electric current flowing in a normal metal or semiconductor can induce a bulk magnetic moment. This effect is known as the Edelstein (EE) or magneto-electric effect. Similarly, in a bulk superconductor a phase gradient may create a finite spin density. The inverse effect, also known as the spin-galvanic effect, corresponds to the creation of a supercurrent by an equilibrium spin polarization. Here, by exploiting the analogy between a linear-in-momentum SOC and a background SU(2) gauge field, we develop a quasiclassical transport theory to deal with magneto-electric effects in superconducting structures. For bulk superconductors this approach allows us to easily reproduce and generalize a number of previously known results. For Josephson junctions we establish a direct connection between the inverse EE and the appearance of an anomalous phase-shift φ0 in the current-phase relation. In particular we show that φ0 is proportional to the equilibrium spin-current in the weak link. We also argue that our results are valid generically, beyond the particular case of linear-in-momentum SOC. The magneto-electric effects discussed in this study may find applications in the emerging field of coherent spintronics with superconductors.