Current-Phase Relations of Superconducting PtSi Constriction Josephson Junctions

In this talk, I will present our recent measurements of the current–phase relations (CPRs) in superconductor–constriction–superconductor (ScS) Josephson junctions fabricated from platinum silicide thin films on silicon substrates. We constructed dc superconducting quantum interference devices (SQUIDs) incorporating pairs of such junctions and measured their magnetic-field-dependent transport characteristics. By comparing the observed supercurrent interference patterns with numerical Ginzburg–Landau simulations, we extracted the CPRs of individual junctions and quantified their nonlinear behavior. Our results show that although the constrictions exhibit strong intrinsic nonlinearity, the effect is moderated by the kinetic inductance of the device leads, which is an important consideration for practical superconducting quantum circuit applications.