Excitation Dynamics in an Inductively Coupled Fluxonium Chain

We propose a highly coherent near-term quantum simulator based on the fluxonium qubits with inductive coupling. This system provides long coherence time, large anharmonicity, and strong coupling, making it suitable to study strongly interacting clean and disordered transverse field Ising models (TFIM). A weak detuning from the sweet spot is equivalent to the additional random longitudinal field in the TFIM. We evaluate the propagation of qubit excitations through the system with quenched flux disorder. In the clean limit, we find that the excitation propagation is in agreement with the TFIM. As the flux disorder increases, the excitations become localized. We demonstrate that the localization and ergodicity in the system can be identified by measuring excitations at the edges. Such measurements do not require tunable couplers and are easily accessible via circuit QED methods. Thus, inductively coupled fluxoniums provide unique opportunities to study localization and many-body effects in highly coherent quantum systems.