Tuesday, November 10, 2009
Two independent teams have, for the first time, created
Bose-Einstein condensates of strontium atoms. The ability to cool
strontium to very low temperatures and control its motion could
lead to increasingly precise clocks and may advance our progress
toward quantum computers and novel experiments in ultracold
chemistry. The new Bose-Einstein condensate is reported in two
papers in Physical Review Letters and highlighted with a Viewpoint
in the November 9 issue of
Physics.
When certain types of atoms are densely packed, then cooled to
less than a millionth of a degree above absolute zero, they
suddenly drop into a single quantum state called a Bose-Einstein
condensate. In effect, the atoms combine to behave as one object
rather than a group of individual pieces. This strange phase of
matter was first observed in 1995 with atoms that had one electron
in their outer shells. Since then researchers have achieved
Bose-Einstein condensates with atoms that have two outer shell
electrons, but a Bose-Einstein condensate of strontium, one of
these atoms, has remained elusive.
Now Simon Stellmer and colleagues at the Universität
Innsbruck in Austria and Natali Martinez de Escobar and colleagues
at Rice University in Texas have used lasers to trap and cool atoms
of the isotope strontium-84 to form a Bose-Einstein condensate. If
researchers can extend this achievement to other isotopes of
strontium, the new Bose-Einstein condensate could improve
ultra-accurate clocks, store information in quantum computers, or
help test fundamental constants of nature.
SOURCE