Spreading many-body entanglement through controlled transport in a quantum fluid

Learning how to create and control highly-entangled many-body systems is a central challenge in modern quantum science. Analog quantum simulators based on superconducting qubits provide a rich and versatile platform for exploring the emergent collective phenomena in synthetic quantum materials. Here, we engineer an array of capacitively coupled transmon qubits to study the dynamics of a Hubbard model for interacting microwave photons, leveraging the precise time- and space-resolved control of the lattice potential landscape. In previous work, we prepared quantum fluids of light using particle-by-particle assembly and adiabatic tuning of disorder. In this talk, we harness the quantum nature of our lattice sites to evolve our quantum fluid under a quantum superposition of different lattice configurations. This ancilla-conditioned many-body dynamics enables the preparation of highly-entangled multi-qubit cat states, which we characterize using a many-body Ramsey interferometry protocol to probe the coherence of their long-range correlations.