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Josephson Current through Semiconductor Nanowire with Spin-Orbit Interaction in Magnetic Field

We theoretically study the DC Josephson effect of a semiconductor nanowire (NW) with strong spin-orbit interaction when a magnetic field is applied parallel to the NW. We adopt a model of single scatterer in a quasi-one-dimensional system for the case of short junctions where the size of normal region is much smaller than the coherent length. In the case of single conduction channel in the model, we obtain analytical expressions for the energy levels of Andreev bound states, $E_n$, and supercurrent $I$, as a function of phase difference $φ$ between two superconductors. We show the 0-$π$ transition by tuning the magnetic field. In the case of more than one conduction channel, we find that $E_n (-φ) \ne E_n (φ)$ by the interplay between the spin-orbit interaction and Zeeman effect, which results in finite supercurrent at $φ=0$ (anomalous Josephson current) and direction-dependent critical current.