Parametric frequency conversion in two coupled superconducting resonators

Abstract

In this work, we have designed, fabricated, and characterized two coupled superconducting microwave resonators. Using this system, we investigate a parametric frequency conversion process in the microwave regime. We modulate the resonance frequency at the difference frequency between two modes, i.e. by three-wave mixing. An incoming signal, resonant with one of the modes, is then converted to the other mode. We demonstrate this behavior in several different schemes, e.g. using one or two modulation tones. We report a conversion efficiency of 50%, meaning that 50% of the incoming wave amplitude gets converted to the other frequency. Finally, we discuss the possibilities to use such a system in a quantum computing architecture.