Claude Cohen-Tannoudji
Cohen-Tannoudji, Claude (1933-), a French physicist, shared the 1997 Nobel Prize in physics with American physicists Steven Chu and William Daniel Phillips for developing methods to cool and trap atoms with laser light.
Trapping atoms means slowing them down until they are almost stationary, so that they can be studied without being disturbed by the constant battering of other atoms. This technique enables scientists to obtain precise measurements of the properties of the atoms. The methods the trio of physicists developed have greatly increased our knowledge of the interaction between radiation and matter. These techniques have led the way to a deeper understanding of the quantum-physical behavior of gases at low temperatures. The methods could lead to the design of more precise atomic clocks for use in space and global navigation.
Cohen-Tannoudji was born on April 1, 1933, in Constantine, Algeria. Algeria at the time was a French colony. He completed his primary and secondary school education in Algiers. After graduating from high school, he left Algiers for Paris in 1953, to attend the École Normale Supérieure. He intended to study mathematics, but switched to physics. During the summer of 1955, he attended school at Les Houches, which offered training in modern physics. He graduated from École Normale Supérieure in 1957. After graduating from École Normale, he joined the military and served 28 months during the Algerian Revolution. He spent part of this time assigned to a scientific department studying the upper atmosphere.
In 1960, he began work on his Ph.D. degree at the École Normale Supérieure in Paris, with a research post at the French National Center for Scientific Research. He finished in 1962. He then taught quantum mechanics at the University of Paris.
In 1973, he was appointed professor of atomic and molecular physics at the Collége de France, Paris, where he still teaches today.