Lecture summary: In 1935, with co-authors Podolsky and Rosen, Einstein discovered an amazing quantum situation, where particles in a pair are so strongly correlated that Schr枚dinger called them 鈥渆ntangled鈥. By analysing that situation, Einstein concluded that the quantum formalism was incomplete. Niels Bohr immediately opposed that conclusion, and the debate lasted until the death of these two giants of physics, in the 1950鈥檚.
In 1964, John Bell produced his famous inequalities, which allowed experimentalists to settle the debate, and to show that the revolutionary concept of entanglement is indeed a reality.
Based on that concept, a new field of research has emerged, quantum information, where one uses quantum bits, the so-called 鈥渜ubits鈥. In contrast to classical bits which are either in state 0 or state 1, qubits can be simultaneously in state 0 and state 1, as a Schr枚dinger cat could be simultaneously dead and alive.
Entanglement between qubits enables conceptually new methods for processing and transmitting information. Large scale practical implementation of such concepts might revolutionise our society, as did the laser, the transistor and integrated circuits, some of the most striking fruits of the first quantum revolution, which began with the 20th century.
Speaker biography: Professor Alain Aspect is a distinguished CNRS scientist and professor at the听 Institut d鈥橭ptique in Palaiseau, France. Born in 1947, he studied at the Ecole Normale Sup茅rieure de Cachan and Universit茅 d鈥橭rsay. His 鈥楨xperimental Tests of Bell鈥檚 Inequalities with Correlated Photons鈥, with Jean Dalibard and Philippe Grangier, were the subject of his doctorate (1983). He then developed, with Philippe Grangier, the first source of single photons, used in experiments on wave-particle duality.
From 1985 to 1992 he worked with Claude Cohen-Tannoudji at the Laboratoire Kastler Brossel de l鈥橢NS and Coll猫ge de France, on cooling atoms with lasers, in particular cooling below the 鈥榦ne photon recoil鈥.
Since 1991, he has been Head of the Group of Atom Optics which he established at the Institut d鈥橭ptique, Palaiseau. Recent scientific projects have included work on Bose-Einstein condensates and atom lasers, quantum atom optics, and quantum simulators with ultra cold atoms. Alain Aspect holds the position of CNRS Distinguished Scientist and Professor at Institut d鈥橭ptique and Ecole Polytechnique, Palaiseau.
He is member of academies in France, USA and Austria. In the recent years, he has been awarded the CNRS Gold Medal (2005), the EPS Quantum Optics Senior Prize (2009) and the Wolf Prize in Physics (2010).
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