Time-frequency encoded single-photon generation and broadband single-photon storage with a tunable subradiant state

An atomic system that can be addressed via a single optical mode, hereafter called a one-dimensional atom, is central for many applications in optical quantum technologies. A cavity with a large Purcell factor is required to collect the emission efficiently, but a small Purcell factor is required for long-time memory storage. Here, we introduce an effective and versatile one-dimensional atom consisting of two interacting quantum emitters efficiently coupled to a cavity mode with a large Purcell factor. The dipole–dipole interaction gives rise to a subradiant state with a tunable bandwidth. We demonstrate generation of time-shaped single photons and implementation of quantum memory. We discuss experimental challenges and practical implementation using different systems.