|This article needs additional citations for verification. (December 2009)|
Ultracold atoms are atoms that are maintained at temperatures close to 0 kelvin (absolute zero), typically below temperatures of some tenths of microkelvins (µK). At these temperatures the atom's quantum-mechanical properties become important. To reach such low temperatures, a combination of several techniques has to be used. First atoms are usually trapped and pre-cooled via laser cooling in a magneto-optical trap. To reach the lowest possible temperature, further cooling is performed using evaporative cooling in a magnetic or optical trap.
If sufficiently low temperatures are reached the atoms form a new state of matter that is governed by quantum mechanics. For bosonic atoms this state is a Bose–Einstein condensate, for fermionic atoms it is a degenerate Fermi gas.
Experiments with ultracold atoms are important for understanding quantum phase transition and studying Bose–Einstein condensation (BEC), bosonic superfluidity, quantum magnetism, many-body spin dynamics, Efimov states, Bardeen-Cooper-Schrieffer (BCS) superfluidity and the BEC-BCS crossover.
- Bloch, Immanuel (2008). "Quantum Gases". Science 319 (5867): 1202. Bibcode:2008Sci...319.1202B. doi:10.1126/science.1152501.
- Rousseau, Valery. "Pure Mott Phases in Confined Ultracold Atomic Systems". Phys. Rev. Lett. 104 (16): 167201. doi:10.1103/PhysRevLett.104.167201.
|This science article is a stub. You can help Wikipedia by expanding it.|