I
spent my 2002-2003 sabbatical year in the metastable-helium group
headed by C. Cohen-Tannoudji and M. Leduc in the Laboratoire Kastler
Brossel of the Ecole Normale Supérieure, Paris.
Bose-Einstein condensation with metastable helium had already been
demonstrated by then, and the group was beginning to shine
near-resonant laser light into their trapped sample in an effort to
excite bound molecular states of helium. When this attempt at
"photoassociation" (PA) of ultracold helium atoms gave its first clear
signs of success in the form of resonant trap loss, and the group found
itself with a twofold aim: experimental characterization of the
PA spectrum and theoretical modeling of the newly observed molecular
resonances. A delightfully energetic graduate student named
Jérémie Léonard (now at Université de Strasbourg) undertook both
aspects of the work as his Ph.D. thesis project. It was my
privilege to be part of his supporting cast, and to work with many
other students, senior researchers, visiting scientists, and
collaborators at ENS. The details of our investigations can be found in
the references listed below.
--M. Walhout
Part of M.W.'s travel expenses were covered by the National Science Foundation (Grant NSF-PHYS-0140135).
project: