Tunable frequency conversion and comb generation with a superconducting artificial atom

TL;DR

This paper demonstrates a tunable superconducting artificial atom system that efficiently generates and controls frequency combs and converts frequencies, promising for integrated quantum optics applications.

Contribution

It introduces a novel, highly tunable superconducting artificial atom setup for frequency conversion and comb generation, with experimental validation matching theoretical predictions.

Findings

Generation of multiple frequency peaks and combs with equal detuning.

Wide tunability over tens of MHz exceeding linewidth.

Potential for integration into quantum optical devices.

Abstract

We investigate the power spectral density emitted by a superconducting artificial atom coupled to the end of a semi-infinite transmission line and driven by two continuous radio-frequency fields. In this setup, we observe the generation of multiple frequency peaks and the formation of frequency combs with equal detuning between those peaks. The frequency peaks originate from wave mixing of the drive fields, mediated by the artificial atom, highlighting the potential of this system as both a frequency converter and a frequency-comb generator. We demonstrate precise control and tunability in generating these frequency features, aligning well with theoretical predictions, across a relatively wide frequency range (tens of MHz, exceeding the linewidth of the artificial atom). The extensive and simple tunability of this frequency converter and comb generator, combined with its small physical footprint, makes it promising for quantum optics on chips and other applications in quantum technology.