Ultracompact cavity array for analog quantum simulation

Photonic cavity arrays form the basis of one of the most promising paradigms for quantum simulation to study complex many-body physics. We developed a non-trivial structured photonic environment that could enable a multimode strong and ultra-strong coupling with a qubit. This platform consists of a unidimensional metamaterial implemented by an array of coupled superconducting microwave cavities made from thin Niobium Nitride (NbN) films. Such disordered superconductor allows to reach a very high kinetic inductance, which presents a two-fold advantage: a) It allows to reach ultra-strong coupling with an artificial atom as the capacitive coupling is proportional to the square root of the resonators' impedance, which can be highly increased thanks to the kinetic inductance; b) It allows to strongly reduce the resonator/metamaterial footprint. Furthermore, working with a metamaterial allows the engineering of a non-trivial photonic dispersion relation, where it is possible to obtain states displaying topological properties (SSH-states). We have been able to fabricate and characterize unidimensional metamaterials made of up to 88 ultra-compact resonators. We are currently expanding this technology to 2D metamaterials, where we expect to engineer further topological photonic states.