The realization of strong interactions between individual photons is a long-standing goal of
both fundamental and technological significance. Scientists have known for over half a …

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

This article reviews recent theoretical and experimental advances in the fundamental
understanding and active control of quantum fluids of light in nonlinear optical systems. In …

Squeezed light generation has come of age. Significant advances on squeezed light
generation have been made over the last 30 years—from the initial, conceptual experiment …

A few decades ago, quantum optics stood out as a new domain of physics by exhibiting
states of light with no classical equivalent. The first investigations concerned single photons …

Quantum information is a rapidly advancing area of interdisciplinary research. It may lead to
real-world applications for communication and computation unavailable without the …

Time crystals are periodic states exhibiting spontaneous symmetry breaking in either time-
independent or periodically-driven quantum many-body systems. Spontaneous modification …

In the third edition the presentation of new topics has been deliberately kept simple for
pedagogical purposes. Chapter 1 was completed by references to the tidal bore and …

This Colloquium examines the field of the Einstein, Podolsky, and Rosen (EPR) gedanken
experiment, from the original paper of Einstein, Podolsky, and Rosen, through to modern …

Quantum non-demolition measurements are designed to circumvent the limitations imposed
by Heisenberg's uncertainty principle when performing repeated measurements of quantum …