A Fock state lattice approach to quantum optics

Abstract: We analyze a set of models frequently appearing in quantum optical settings by expressing their Hamiltonians in terms of Fock-state lattices. The few degrees-of-freedom of such models, together with the system symmetries, make the emerging Fock-state lattices rather simple such that they can be linked to known lattice models from the condensed matter community. This sheds new light on known quantum optical systems. While we provide a rather long list of models and their corresponding Fock-state lattices, we pick a few ones in order to demonstrate the strength of the method. The three-mode boson model, for example, is shown to display a fractal spectrum, and chiral evolution in the Fock-state lattice characterized by localized distributions traversing along symmetric trajectories. In a second example we consider the central spin model which generates a Fock-state lattice reminiscent of the SSH-model hosting topological edge states. We further demonstrate how the phenomena of flat bands in lattice models can manifest in related Fock-state lattices, which can be linked to so called dark states.