Supercurrent-phase relationship of a Nb/InAs(2DES)/Nb Josephson junction in overlapping geometry

Superconductor/normal conductor/superconductor Josephson junctions with highly transparent interfaces are predicted to show significant deviations from sinusoidal supercurrent-phase relationships (CPR) at low temperatures. We investigate experimentally the CPR of a ballistic Nb/InAs(2DES)/Nb junction in the temperature range from 1.3 K to 9 K using a modified Rifkin-Deaver method. The CPR is obtained from the inductance of the phase-biased junction. Transport measurements complement the investigation. At low temperatures, substantial deviations of the CPR from conventional tunnel-junction behavior have been observed. The data are fitted with a model presented by Grajcar et al. [Physica C 372-376, 27 (2002)], yielding good agreement.