Transcript Bose-Einstein Condensation

Bose-Einstein Condensation
It’s pretty cool
Where it all began
Bose
Einstein
• (1924) Indian S.N. Bose derives the Planck law for black-body
by treating photons as a gas of identical particles
• Einstein later generalizes Bose’s theory, for an ideal gas of
identical molecules
• Lead to the prediction of a new form of matter
A bit of an explanation
• As the temperature is lowered
the molecules of the gas collapse
into the ground state
• In the lowest energy state the
molecules blur together and form
the Condensate
• So, Bose-Einstein condensate is
just a collection of identical
atoms smeared together in the
lowest quantum-energy state
• Although the prediction had been
around since the 1920’s, it wasn’t
realized until 1995 by Eric Cornell
and Carl Weiman of Colorado
University
The formation BEC from left to right
How do we make it?
• Well, we cool some gas…
• This is actually harder to do than it
sounds: the gas must be cooled down
to a few microKelvin, or less
• It must also be kept Isolated from its
surroundings
• In a typical Cooling apparatus there
are four main sections
–
–
–
–
Vacuum Pump
Trap
Laser Cooling System
Evaporative Cooling System
Strange Properties
•
•
•
•
•
Superfluid
Optically Dense
Magnetically Hypersensitive
Laser-like: Coherent matter waves
Solitons
• Fermionic-Condensate
• Bosenova
Bose-nova
Super-nova
That’s Neat, but What is it good for?
• Bose-Einstein Condensate is still, for the most part in its
infancy.
• Despite this, there have been few tentative ideas about
applications of BEC
• Those few that have been formed stem from BEC’s extreme
sensitivity to its environment
• The only immediate reward for study of BEC is to further
our understanding of Quantum Physics
• There is hope for the future though: BEC bears a striking
resemblance to the early laser
That’s all…for now
• BEC-a new form of matter which is
achieved when enough atoms of a gas
are trapped together at the ground-state
energy level
• Great Experimental potential: it could be
quite some time before we’ve explored all
the facets of this interesting condensate
• While you won’t be buying any BEC-based
products in the near future, you’ll
probably be hearing more about it as
research continues…
References
http://www.wikipedia.org
http://www.colorado.edu/physics/2000/index.pl
http://www.mpq.mpg.de/qdynamics/projects/bec/bec.html
http://www.physorg.com/news6303.html
http://www.exn.ca/dailyplanet/story.asp?id=2002011152
http://www-lplgb.univ-paris13.fr/Gb/Equipes/GroupeCOMETA/GroupeCOMETA.htm
http://physicsweb.org/articles/world/10/3/3
http://www.light-science.com/phys2.html
http://physics.nist.gov/Pubs/Bec/TofCont.html
Thanks to Phil for help with my pictures