Josephson Current Anomalies in Spin-Orbit Nanowires

We study the anomalous Josephson effect in a nanowire with Rashba spin-orbit interaction and Zeeman spin splitting, contacted with two s-wave superconducting leads with either one or two open conducting channels in the wire. In both cases, we find that the Josephson current is zero at a value phi(0) not equal 0, pi of the phase difference between the order parameter of the leads. While in the former case the critical current is direction independent, in the latter case we observe an asymmetry between Ic+ (the maximum Josephson current from left to right) and Ic- up to about 20%.