Hanbury Brown and Twiss, Hong Ou and Mandel effects and other landmarks in quantum optics: from photons to atoms

Abstract

The second quantum revolution is based on the concept of entanglement and the ability to observe and manipulate individual quantum objects. This notion was prompted by celebrated quantum optics landmark experiments. The author’s group has endeavored to revisit these experiments with atoms instead of photons, more precisely metastable helium atoms (He*), which can be detected one by one, as photons. The first landmark that announced the beginning of modern quantum optics was the Hanbury Brown and Twiss effect: it has been studied not only with 4He* atoms, which are bosons, but also with 3He* atoms, which are fermions. The group has then observed the atomic Hong Ou and Mandel effect, and, more recently, shown the possibility to use a slightly generalized scheme to test Bell’s inequalities with atoms entangled in momentum.