Josephson effect between conventional and non-centrosymmetric superconductors

Hayashi, Nobuhiko; Iniotakis, C.*; Machida, Masahiko  ; Sigrist, M.*

We analyze the Josephson effect between a conventional superconductor (SC) and a non-centrosymmetric SC with the purpose to identify qualitative features originating form the pairing symmetry of the latter. As a concrete example, we consider the non-centrosymmetric SC CePtSi where Rashba spin-orbit coupling plays a crucial role and affects the Josephson pair tunneling. We find that the Josephson coupling is composed of two parts, a spin-singlet-like component and a spin-triplet-like one. The triplet-like component can lead to a Josephson coupling that is shifted by relative to the singlet-like coupling. This has important implications on the interference effects and may explain some recent experimental results for the Al/CePtSi junction.