Cooling Bose-Einstein condensates below 500 picokelvin.
Spin-polarized gaseous Bose-Einstein condensates were confined by a combination of gravitational and magnetic forces. The partially condensed atomic vapors were adiabatically decompressed by weakening the gravito-magnetic trap to a mean frequency of 1hertz, then evaporatively reduced in size to 2500 atoms. This lowered the peak condensate density to 5 x 10(10) atoms per cubic centimeter and cooled the entire cloud in all three dimensions to a kinetic temperature of 450 +/- 80 picokelvin. Such spin-polarized, dilute, and ultracold gases are important for spectroscopy, metrology, and atom optics.
Leanhardt
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Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. ael@mit.edu
Pasquini
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Saba
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Schirotzek
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A
Shin
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Y
Kielpinski
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Pritchard
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Ketterle
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