Serge Haroche

Origins and early life

Serge Haroche was born into a Jewish family in Casablanca on 11 September 1944.

Work and career

His father Albert, a lawyer trained in Rabat, was one of seven children of Isaac and Esther Haroche, teachers at the school of the Alliance israélite universelle; both of Serge's paternal grandparents had themselves been pupils of the Alliance, in Marrakesh and in Tétouan. His mother Valentine Roubleva was a teacher born in Odessa to a Jewish family of physicians who moved to Morocco in the early 1920s, so that the household joined Sephardi and Ashkenazi lines.

The family left Morocco in 1956, at the end of the French protectorate, and settled in France, where he took his doctorate in 1971 at the University of Paris under Claude Cohen-Tannoudji. Quantum mechanics had always been argued about with imaginary apparatus, because to observe a single particle was normally to destroy it — a photon striking a detector is absorbed and gone. Haroche's group at the École normale supérieure built a way round this: a single microwave photon is trapped between two superconducting mirrors so reflective that it survives almost a tenth of a second, bouncing forty thousand kilometres — once around the Earth, and atoms in highly excited states are sent through one at a time, each leaving with its phase nudged by the photon it never touched.

Reading the atoms gives the photon's state without taking it, so that a quantum object can be watched over time — including the moment it loses its coherence to the outside world.

Recognition

He has held the chair of quantum physics at the Collège de France since 2001 and shared the 2012 Nobel Prize in Physics with David Wineland, who reached the same ground from the other side, controlling trapped ions with light.