I will report on the localization of atoms of a BEC suspended against gravity and released in a 3D correlated optical disorder (correlation length less than 0.3 ¿m along any axis). The 3D laser speckle disorder has been engineered so that there is no possibility of classical or quantum trapping of the atoms in the local minima of the disordered potential. A phenomenological analysis allows us to distinguish a localized and a diffusive part, and to measure their weights vs. the disorder amplitude. These experimental results are compatible with the results of the self consistent theory of Anderson Localization applied to our specific situation. To conclude, I will discuss the limitations of the present scheme and the prospects of improvements in order to determine precisely the value of the mobility edge and the critical behavior.
Born in 1947, Alain Aspect studied at the Ecole Normale Supérieure de Cachan and Université d’Orsay. After a master thesis on holography and a three years teaching assignment in Cameroon, he started, in 1974, a series of experiments on the foundations of quantum mechanics. His “Experimental Tests of Bell’s Inequalities with Correlated Photons”, were the subject of his doctorate thesis presented in 1983. In 1983-86, with his student Philippe Grangier, he developed the first source of single photons and performed fundamental experiments on wave-particle duality of light. From 1985 to 1992 he worked with Claude Cohen-Tannoudji at the Laboratoire Kastler Brossel de l’ENS and Collège de France, on cooling atoms with lasers, in particular “cooling below the one photon recoil”. Since 1991, he is head of the Atom Optics group that he has established at the Institut d’Optique, now in Palaiseau. Recent scientific production concerns mainly Bose Einstein Condensates, Atom Lasers, Quantum Atom Optics with metastable Helium, Anderson localization of ultracold atoms. A CNRS senior scientist (”Directeur de recherches CNRS”) at Laboratoire Charles Fabry de l’Institut d’Optique, Alain Aspect is also a professor at Institut d’Optique and Ecole Polytechnique, Palaiseau. He is a member of the French Académie des Sciences, and of the Académie des Technologies, as well as of foreign academies (NAS, USA; OAW, Austria). He has received major awards, among them the OSA Max Born award (1999), the CNRS Gold Medal (2005), the Quantum Optics senior prize of the European Physical Society (2009), the Wolf prize in Physics (2010).
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