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Professor Wolfgang Ketterle
of RLE wins the 2001 Nobel Prize in Physics
Cambridge, MA 10.09.2001
 The Royal Swedish
Academy of Sciences has named Professor
Wolfgang Ketterle of the Research
Laboratory of Electronics (RLE) one of the three recipients of the 2001 Nobel
Prize in Physics for the achievement of Bose-Einstein condensation in
dilute gases of alkali atoms, and for early fundamental studies of the
properties of the condensates. In addition to being a member of RLE,
Professor Ketterle is an investigator in the MIT-Harvard Center
for Ultracold Atoms (CUA).
Professor
Ketterle's co-recipients are Dr.
Eric A. Cornell of JILA and the National Institute of Standards and
Technology and Dr. Carl
E. Wieman of JILA and the University of Colorado at Boulder. Dr. Cornell was a
graduate research assistant in RLE's Atomic,
Molecular, and Optical Physics group before receiving his doctorate from MIT
in 1990, while Dr. Wieman was an MIT undergraduate in this group before
being graduated from MIT in 1973.
The text of the official Nobel Prize
press release follows:
New State of Matter Revealed:
Bose-Einstein Condensate
A laser beam differs from the light from an ordinary light bulb
in several ways. In the laser the light particles all have the
same energy and oscillate together. To cause matter also to
behave in this controlled way has long been a challenge for
researchers. This year's Nobel Laureates have succeeded they
have caused atoms to "sing in unison" thus discovering
a new state of matter, the Bose-Einstein condensate (BEC).
In 1924 the Indian physicist Bose
made important theoretical calculations regarding light particles. He sent
his results to Einstein who extended the theory to a certain type of atom.
Einstein predicted that if a gas of such atoms were cooled to a very low
temperature all the atoms would suddenly gather in the lowest possible
energy state. The process is similar to when drops of liquid form from a
gas, hence the term condensation.
Seventy years were to pass before
this year's Nobel Laureates, in 1995, succeeded in achieving this extreme
state of matter. Cornell and Wieman then produced a pure condensate of
about 2 000 rubidium atoms at 20 nK (nanokelvin), i.e. 0.000 000 02
degrees above absolute zero.
Independently of the work of
Cornell and Wieman, Ketterle performed corresponding experiments with
sodium atoms. The condensates he managed to produce contained more atoms
and could therefore be used to investigate the phenomenon further. Using
two separate BECs which were allowed to expand into one another, he
obtained very clear interference patterns, i.e. the type of pattern that
forms on the surface of water when two stones are thrown in at the same
time. This experiment showed that the condensate contained entirely co-ordinated
atoms. Ketterle also produced a stream of small "BEC drops"
which fell under the force of gravity. This can be considered as a
primitive "laser beam" using matter instead of light.
It is interesting to speculate on areas for the application of BEC. The
new "control" of matter which this technology involves
is going to bring revolutionary applications in such fields
as precision measurement and nanotechnology.
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