Quantum information processing based on Rydberg atoms emerged as a promising
direction two decades ago. Recent experimental and theoretical progresses have shined …

Photon-photon scattering in vacuum is extremely weak. However, strong effective
interactions between single photons can be realized by employing strong light-matter …

In this review we discuss the works in the area of quantum simulation and many-body
physics with light, from the early proposals on equilibrium models to the more recent works …

The fundamental properties of light derive from its constituent particles—massless quanta
(photons) that do not interact with one another. However, it has long been known that the …

By mapping the strong interaction between Rydberg excitations in ultra-cold atomic
ensembles onto single photons via electromagnetically induced transparency, it is now …

An all-optical transistor is a device in which a gate light pulse switches the transmission of a
target light pulse with a gain above unity. The gain quantifies the change of the transmitted …

Optical qubits uniquely combine information transfer in optical fibers with a good processing
capability and are therefore attractive tools for quantum technologies. A large challenge …

All-optical switching is a technique in which a gate light pulse changes the transmission of a
target light pulse without the detour via electronic signal processing. We take this to the …

We use a microwave field to control the quantum state of optical photons stored in a cold
atomic cloud. The photons are stored in highly excited collective states (Rydberg polaritons) …

A deterministic photon-photon quantum logic gate is a long-standing goal. Building such a
gate becomes possible if a light pulse containing only one photon imprints a phase shift of π …