Current-phase relations as determinants of superconducting thin-film weak-link I-V characteristics

The dc I-V characteristics of superconducting thin-film Sn-Au proximity bridges and uniform-thickness Sn microbridges have been carefully analyzed as a function of the directly measured current-phase relation (CPR). At sufficiently low dc current and voltage levels where heating and relaxation time effects are not important, the I-V characteristics are very well described by a shunted weak-link model that includes the proper dc CPR and a shunt resistance.