Surface effects in magnetic superconductors with a spiral magnetic structure

Abstract

We consider a magnetic superconductor MS with a spiral magnetic structure. On the basis of generalized Eilenberger and Usadel equations we show that near the boundary of the MS with an insulator or vacuum the condensate (Gor'kov's) Green's functions are disturbed by boundary conditions and differ essentially from their values in the bulk. Corrections to the bulk quasiclassical Green's functions oscillate with the period of the magnetic spiral, $2\pi /Q$, and decay inside the superconductor over a length of the order $v/\pi T$ (ballistic limit) or $\sqrt{D/\pi T}$ (diffusive limit). We calculate the dc Josephson current in an MS/I/MS tunnel junction and show that the critical Josephson current differs substantially from that obtained with the help of the tunnel Hamiltonian method and bulk Green's functions.

10 pages 3 Figs; some misprints in fromulae corrected; submitted to Phys. Rev. B

References in corpus (4)

• Odd-frequency pairing in normal metal/superconductor junctions
• Josephson effect due to the long-range odd-frequency triplet superconductivity in SFS junctions with Neel domain walls
• Long-range odd triplet superconductivity in SF structures with Neel walls
• Josephson effect in thin-film superconductor/insulator/superconductor junctions with misaligned in-plane magnetic fields