Scalable quantum circuits for many-body quantum optics simulations

We consider a model describing a system of many quantum emitters coupled through a radiation bath. By adopting an efficient mapping of the bosonic modes onto qubits, we implement quantum circuits, compatible with NISQ (Noisy Intermediate-Scale Quantum) era systems, that allow us to investigate the dynamics of the ensemble as a function of various parameters of the ensemble, including the number of emitters, the spectral inhomogeneity in the system, the emission lifetime of isolated emitters and the spatial separation between emitters. The quantum algorithms afford us the capacity to precisely track the emergence of cooperative dynamics, manifested through superradiant emission, as the system is tuned towards optimal coupling with respect to various parameters. These quantum algorithms avoid approximations performed in conventional studies of many-emitter systems and provide a robust and intuitive characterization. Despite being limited to a small number of qubits, they are found to provide a reliable characterization validated by comparison with analytical solutions and classical computation results in their respective regimes of validity.