Prix des Trois Physiciens : From quantum measurement to quantum simulations with Rydberg atoms

Michel Brune (Laboratoire Kastler Brossel) — October 3, 2017 — Award ceremony and special seminar by the 2017 recipient of the "Prix des Trois Physiciens"


Abstract :
Rydberg atoms have many exaggerated properties with respect to ordinary atomic levels with lower energy. Their large orbital corresponds to huge dipoles, strongly coupled to microwave fields. We used this feature for probing a field made of a few microwave photons trapped in a high Q superconducting cavity. We will present experiments achieving non-destructive photons counting, and exhibiting some of the most intriguing feature of quantum measurements : state projection, quantum jumps and decoherence of Schrödinger kitten states.
The unprecedented polarizability of Rydberg atoms makes then exhibit unusually strong dipole-dipole interaction. Spontaneous emission of circular Rydberg atoms can also be strongly suppressed by using metallic structures controlling the radiation field mode density. We propose the construction of a quantum simulator of XXZ spin chain or ladder Hamiltonian by using linear chains of trapped circular Rydberg atoms. We will discuss open condensed matter problems, which may be addressed with this simulator.

Biography :
Michel Brune is a senior CNRS researcher working in the Laboratoire Kastler Brossel at École Normale Supérieure, and a professor at École Polytechnique.
He and his team (with Serge Haroche and Jean-Michel Raimond) made seminal contributions to the field of cavity QED. Amongst other remarkable accomplishments, he realized a series of experiments achieving quantum non-demolition photon counting, revealing essential features of quantum measurement.
Michel was already awarded several prizes such as the "Grand prix Ampère de l’électricité de France” of the French Academy of Sciences (1998), and the "Fabry-de-Gramont” prize of the French Optical Society (2001).

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