Electrically driven, singly degenerate three-wave mixing in the Josephson Ring Modulator

Parametric amplifiers are now a required component of superconducting quantum information processors. One of the most conceptually attractive ways to produce parametric amplification is the modulation of a single mode’s resonant frequency with a drive at twice that frequency. This is regularly achieved in superconducting circuits via flux pumping a SQUID-based resonator. However, this typically requires multi-layer fabrication and crossovers to tightly couple a microwave flux into the amplifying mode. As an alternative, we exploit broken symmetries in a flux-biased, inductively-shunted Josephson Ring Modulator (JRM). In this circuit, the multiple spatial modes of the JRM play the roles of the drive line and amplifying mode, providing the equivalent of tight flux coupling with good spectral and spatial pump isolation in a simple, single-layer device. Moreover, this adds yet another primitive to the library of parametric couplings available to power next-generation, multiply-driven JRM-based circuits. We will present data on this mode of operation and discuss its performance as compared against conventional phase-preserving amplification in the same device.