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Physicist Murray holland of Jila has
proposed using atomtronics to move
individual atoms (red) between loca-
tions in an optical lattice (blue).
the lowest setting for their ring, about
one revolution every second.
Because the condensate also happens
to be frictionless, this ring should, in
theory, rotate forever. Limited by technical difficulties, the research team kept it
going for about 40 seconds, the lifetime
of the condensate.
“This is the first time that someone
has actually made a ring-shaped conden-
sate,” says team member and physicist
Gretchen Campbell. “We’re hoping to
use this condensate in much the way
that superconductors have been used
to make improved devices and sensors.”
Her first idea for a useful device was
inspired by sensors that respond to very
weak magnetic fields, called supercon-
ducting quantum interference devices,
or SQUIDs. These devices, loops of
superconductors used as detectors
in medical scanners, change current
suddenly when a barrier to the flow of
electrons through the loop is triggered
by a magnetic field.
Back Story
Birth of the Ultracool
Physicists Satyendra Nath bose and
Albert Einstein proposed in 1924
that large numbers of atoms could be
chilled to the point that they joined
together in a single quantum state,
bringing subatomic effects to a scale
accessible by laboratory experiments.
but it wasn’t until 1995 that scientists
made a bose-Einstein condensate,
using lasers to carefully cool rubid-
ium-87 atoms down to temperatures
less than a millionth of a degree above
absolute zero. the 2001 Nobel Prize
in Physics celebrated this accomplishment, which was also achieved using
sodium atoms. this image shows the
distribution of atomic velocities in a
rubidium gas just before (left) and after
(center and right) the formation of
a condensate.
