Quantum simulation of strong interaction of light and matter

ended

Quantum optics describes the emission and absorption of radiation by quantum systems. The most interesting effects of the coupling between quantum emitters and their environment (a bath) appear when this coupling becomes strong. If multiple quantum emitters are coupled strongly to the same bath, the emitters themselves interact strongly via the bath, opening the way to engineered many-body quantum systems with interesting radiative properties, such as directional emission, chirality, and subradiance. However, fundamental and technical issues limit the coupling strength achievable with state-of-the-art experimental platforms: emitters placed in microcavities or coupled to nanophotonic structures. To circumvent these issues, the applicant proposes to realize an analog quantum simulation of quantum emitters strongly coupled to baths with engineered band structures in one and two dimensions. In this quantum simulation all relevant parameters will be arbitrarily tunable allowing the realization of all system regimes, including the strong coupling regime. This tunability will be achieved by replacing the quantum emitter with an artificial two-level quantum system. Ultracold strontium atoms trapped in optical lattices will be used for this purpose. The implemented quantum simulator will be used to realize and directly image bound states in one and two dimensions that could enable strong long-range atom-atom interactions. Furthermore, by tailoring the emission direction and dynamics of multiple emitters in 1D and 2D, unprecedentedly long-lived subradiant states will be engineered, with applications in precision measurements, metrology, and quantum computing. This project will also open up the possibility of going beyond the physics of photonic baths and engineering both noninteracting and strongly-interacting baths, consisting of either bosonic or fermionic particles, that have no analog in quantum optics.