Ballistic Josephson junctions in the presence of generic spin dependent fields

François Konschelle (1) , Ilya V. Tokatly (2, 3) , F. S. Bergeret (1, 4)

1 CFM-MPC - Centro de Fisica de Materiales
2 nanobio - Nano-Bio Spectroscopy group
3 Ikerbasque - Basque Foundation for Science
4 DIPC - Donostia International Physics Center

Ballistic Josephson junctions are studied in the presence of a spin-splitting field and spin-orbit coupling. A generic expression for the quasi-classical Green's function is obtained and with its help we analyze several aspects of the proximity effect between a spin-textured normal metal (N) and singlet superconductors (S). In particular, we show that the density of states may show a zero-energy peak which is a generic consequence of the spin-dependent couplings in heterostructures. In addition we also obtain the spin current and the induced magnetic moment in a SNS structure and discuss possible coherent manipulation of the magnetization which results from the coupling between the superconducting phase and the spin degree of freedom. Our theory predicts a spin accumulation at the S/N interfaces, and transverse spin currents flowing perpendicular to the junction interfaces. Some of these findings can be understood in the light of a non-Abelian electrostatics.

Mots clés: Josephson junction; superconducting heterostructures; current-phase relation; spin current; spin polarization; spin capacitor; transverse spin current; spin-dependent density of states; ballistic mesoscopic system; spin-orbit; magnetic texture; zero-energy peak; transport equation; gauge-covariant quasi-classic Green functions

Domaines: Supraconductivité [cond-mat.supr-con]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

François Konschelle, Ilya V. Tokatly, F. S. Bergeret. Ballistic Josephson junctions in the presence of generic spin dependent fields. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2016, 94, pp.014515. ⟨hal-01495981⟩