Field-induced phase-matching in Josephson traveling wave parametric amplifiers

arXiv:2611.13084v1 Announce Type: new Abstract: Superconducting Josephson traveling wave parametric amplifiers (JTWPAs) enable broadband, quantum-limited amplification of weak microwave signals. JTWPAs are essential for the single-shot readout of superconducting qubits, broadband vacuum squeezing, or the generation of microwave cluster states. Phase-matching between signal and pump modes in such JTWPAs represents a major engineering challenge, which is typically solved by integrating resonators in a nonlinear medium in order to tailor electromagnetic dispersion relations and achieve a broadband, high-gain amplification. Here, we experimentally demonstrate a phase-matching approach using a homogeneous nonlinear medium based on Josephson elements by exploiting a magnetic field inhomogeneity.