Chiral cavity quantum electrodynamics in a 3D microwave lattice coupled to a transmon qubit (Part 1)*

Recent advancements in the ability to create and manipulate superconducting quantum systems have created an exciting opportunity to construct from the ground up quantum materials tailored to host rich interactions. We have designed a two-dimensional meta-material in which microwave photons inhabiting a lattice of superconducting 3D microwave cavities interact strongly with ferrimagnets, realizing a quarter-flux Hofstadter model for light. We perform state tomography on the lattice and demonstrate chiral, time-reversal symmetry broken edge transport with lifetimes ~1000 times larger than the site to site tunneling rate. This is the first photonic topological lattice platform compatible with strong interactions. We have coupled a single transmon qubit to this lattice, enabling this platform to study chiral cavity quantum electrodynamics. Here we discuss the design and testing of this system and describe prospects for its application.