Laser Manipulation of Atoms

Lecture presented by: Claude Cohen-Tannoudji
Date: November 15, 2011
Location: BUAA University – Beijing, China

Light is an essential source of information on the world around us, not only at the microscopic scale of atoms and molecules, but also at the very large scale of the universe. It appears now that light is also a powerful tool for acting on atoms, for manipulating them, for controlling their various degrees of freedom. A simple description will be given of the physical mechanisms allowing atoms to be trapped and cooled at extremely low temperatures, billion times lower than room temperatures. A few recent applications of these ultracold atoms will be also described, including very precise atomic clocks with an unprecedented accuracy, the realization of new states of matter such as Bose-Einstein condensates, matter waves and atom lasers. The description of this research field will be taken as an example showing how basic research is essential for improving our understanding of the world and for giving rise to a wealth of important applications.

Claude Cohen- Tannoudji was born on April 1, 1933 in Constantine. Upon completion of his primary and secondary school education in Algiers, Cohen-Tannoudjii attended Paris’ Ecole Normale Supérieure. In his first year, 1953, he attended lectures in mathematics by Henri Cartan and Laurent Schwartz and in physics by Alfred Kastler. Cohen-Tannoudjii found Kastler's lectures so stimulating, that he changed his concentration form mathematics to physics.

In 1955, he joined Kastler's group to do his diploma work. Cohen-Tannoudjii remembers, "The equipment was rather poor and we did what we could without computers, recorders and signal averagers. We measured resonance curves point by point with a galvanometer, each curve five times, and then averaged by hand. We were, somehow, able to get nice curves and exciting results. I think that what I learned during that period was essential for my subsequent research work and key personalities such as Alfred Kastler and Jean Brossel certainly had a significant role in it. We were going together… to attend lectures given by Albert Messiah on quantum mechanics, by Anatole Abragam on NMR and by Claude Bloch on nuclear physics."