Magnetic anisotropy of critical current in nanowire Josephson junction with spin-orbit interaction

We develop and study theoretically a minimal model of semiconductor nanowire Josephson junction that incorporates Zeeman and spin-orbit effects. The DC Josephson current is evaluated from the phase-dependent energies of Andreev levels. Upon changing the applied magnetic field, the critical current oscillates manifesting cusps that signal the 0-pi transition. Without spin-orbit interaction, the oscillations and positions of cusps are regular and do not depend on the direction of the magnetic field. In the presence of spin-orbit interaction, the magnetic-field dependence of the current becomes anisotropic and irregular. We investigate this dependence in detail and show that it may be used to characterize the strength and direction of the spin-orbit interaction in experiments with nanowires. Copyright (C) EPLA, 2014