A Bose–Einstein condensate is a state of matter of bosons confined in an external potential and cooled to temperatures very near to absolute zero. Under such super cooled conditions, a largefraction of the atoms collapse into the lowest quantum state of the external potential, at which point quantum effects become apparent on a macroscopic scale.
This state of matter was first predictedby Satyendra Nath Bose in 1925. Bose submitted a paper to the Zeitschrift für Physik but was turned down by the peer review. Bose then took his work to Einstein who recognized its merit and had itpublished under the names Bose and Einstein.
Not until 1995 was one actually created. The problem was to achieve a cold enough gas without it becoming a liquid or solid first. This was accomplished byEric Cornell, Carl Wieman, and their coworkers in Colorado using a gas of rubidium atoms. The atoms were first cooled and trapped by six intersecting beams of laser light. The atoms would only absorbphotons coming towards them, which would slow the atoms and cool the assembly as well as push the atoms together and away from the warm walls of the chamber. To get the assembly still colder, the laserwere turned off and a magnetic field held the slower atoms together while allowing the faster ones to escape. Finally, when the temperature was down to under 10-7 K-a tenth of a millionth of a degreeabove absolute zero- about 2000 Rubidium atoms came together in a Bose-Einstein condensate 10 micrometers long that lasted for 20s.
Two examples of materials containing Bose-Einstein condensatesare superconductors and superfluids. Superconductors conduct electricity with virtually zero electrical resistance: Once a current is started, it flows indefinitely. The liquid in a superfluid also...