ALP Seminar - Many-particle entanglement and quantum metrology with fiber cavities

Many-particle entanglement is a resource for almost all quantum technologies, but also an active research subject of its own. One powerful way of creating entanglement in a collection of quantum emitters (such as cold or thermal atoms) is to couple them to a single mode of radiation in a cavity. I will discuss how fiber Fabry-Perot microcavities have enabled new ways of entanglement generation and analysis, and how we have recently used them to create spin-squeezed states in an atomic clock with ultracold rubidium atoms. In this experiment in collaboration with the French national metrology laboratory SYRTE, the coherence time of these multiparticle-entangled states reaches 600ms, more than two orders of magnitude longer than in earlier experiments.