Parametrically controlled chiral interface for superconducting quantum devices (Cao et al)

Our first experimental paper is finally on the arXiv!
Xi and team have realized an on-chip circulator that can be interfaced seamlessly with superconducting qubits.

We have developed a circuit composed of 3 flux-tunable ‘SNAIL’ resonators. By parametrically driving these, we can route microwave photons nonreciprocally.


  • The first prototype is already very good — the directionality is about 1000x;
  • Knowing the basic parameters of the circuit from calibrations, the entire behavior can be modeled quantitatively.
  • From analyzing parameters and model, we think this can be used as a very high-efficiency directional interface for superconducting qubits, for example to isolate them from noise, or to route quantum states in a network of qubits.

Link to the preprint: