Cohen-Tannoudji was educated at the École Normale Supérieure
(ENS), Paris, receiving his doctorate in 1962. After graduating, he
continued to work as a research scientist in the department of physics
at ENS while also teaching at the University of Paris VI from 1964 to
1973 and at the Collège de France from 1973 to 2004.
Cohen-Tannoudji and his
colleagues at ENS expanded on
the work of Chu and Phillips,
successfully explaining a
seeming discrepancy in theory
and devising new mechanisms
for cooling and trapping atoms
with laser light. In 1995 they
cooled helium atoms to within
eighteen-millionths of a degree
above absolute zero (−273.15°
C, or −459.67° F), with a
corresponding speed of about
two centimeters per second.
Their work, and that of Chu and
Phillips, furthered scientists’
understanding of how light and
matter interact. Among other
practical applications, the
techniques they developed can
be used to construct atomic
clocks and other instruments
capable of an extremely high
degree of precision.