Chiral cavity quantum electrodynamics in a 3D microwave lattice coupled to a transmon qubit*

Recent advancements in superconducting quantum systems have created an exciting opportunity to construct from the ground up quantum materials hosting rich interactions. We explore cavity quantum electrodynamics of a superconducting transmon qubit strongly coupled to a lattice of 3D microwave resonators engineered to host a synthetic magnetic field for photons. This metamaterial is the first photonic topological lattice platform compatible with strong interactions. We share recent results [1]: we demonstrate transport in the spectrally distinct chiral edge channels of this system, employ strong transmon-lattice coupling to count photons in lattice edge modes, and observe the Lamb shift on the qubit from the synthetic vacuum of the lattice spectrum. We further discuss progress towards measurements with two transmons coupled to this topological photonic material, a setup which should enable quantum communication in chiral lattice edge channels and represent a step towards engineering topological many-body physics for photons.

[1] Owens et al., arXiv:2109.06033