Mixing of coherent waves on a single three-level artificial atom

TL;DR

This paper demonstrates coherent frequency conversion in the gigahertz range using a three-level artificial atom with a cyclic level configuration, enabling potential applications in quantum electronics.

Contribution

It introduces a method for coherent frequency conversion on a single artificial atom with a cyclic three-level structure, realized with a flux qubit.

Findings

Successful demonstration of three-wave mixing on a single artificial atom

Direct measurement of coherent emission at sum and difference frequencies

Potential for integration into quantum electronic devices

Abstract

We report coherent frequency conversion in the gigahertz range via three-wave mixing on a single artificial atom in open space. All frequencies involved are in vicinity of transition frequencies of the three-level atom. A cyclic configuration of levels is therefore essential, which we have realised with an artificial atom based on the flux qubit geometry. The atom is continuously driven at two transition frequencies and we directly measure the coherent emission at the sum or difference frequency. Our approach enables coherent conversion of the incoming fields into the coherent emission at a designed frequency in prospective devices of quantum electronics.