His maternal grandmother was from Chisinau. Since 2001, Haroche is a Professor at the Collège de France and holds the Chair of Quantum Physics. In 1971 he defended his doctoral thesis in physics at the University of Paris VI: his research had been conducted under the direction of Claude Cohen-Tannoudji. Haroche works primarily in atomic physics and quantum optics. He is principally known for showing quantum decoherence by experimental observation, while working with colleagues at the École normale supérieure in Paris in 1996. After a PhD dissertation on dressed atoms under the supervision of Claude Cohen-Tannoudji (himself a Nobel Prize re- cipient) from 1967 to 1971, he developed new methods for laser spectroscopy, based on the study of quantum beats and superradiance. He then moved on to Rydberg atoms, giant atomic states particularly sensitive to microwaves, which makes them well adapted for studying the interactions between light and matter. He showed that such atoms, coupled to a superconducting cavity containing a few photons, are well-suited to the testing of quantum decoherence and to the realiza- tion of quantumlogic operations necessary for the treatment of quantum information. Since 2001, Haroche has been a Professor at the Collège de France and holds the Chair of Quantum Physics. He is a member of the Société Française de Physique, the European Physical society and a fellow and member of the American Physical Society.