Bose-Einstein condensate production

Fig. 8.6. Schematic of a proposed configuration for the production of conditions for Bose-Einstein condensation of positronium using a pulsed, brightness-enhanced positron beam (see text for details). Reprinted from Physical Review B 49, Platzman and Mills, Possibilities for Bose condensation of positronium, 454-458, copyright 1994 by the American Physical Society.

An alternative approach is the Slave Boson approximation [21] where the Fermionic operators are defined as the product of Boson and spin operators. There is a constraint with the number of Fermions, n /, and number of Bosons, n n f - - m, = 1. The spin part is treated with a RVB spin model and the charge as a Bose-Einstein condensation problem. These leads to a fractionalization of charges (holons) and spin (spinons), where uncondensed holons exist above the SC domain. The temperature crossover of the spinon pairing and the holon condensation, as a function of doping, is identified as peak in the SC domain. 

Axions come out of a sort of Bose-Einstein condensation in the early universe rather than from a state of thermal equilibrium, and so will be cold no matter how small their masses. Kolb and Turner in their 1990 duograph (59) gave them a whole chapter (chapter 10), and nothing seems to have happened since to make them a less serious candidate, though the masses must now be in the smaller of the two ranges then possible, near 1 O 5 eV, to keep decay products below detectability (ApOl, Sect. 12.5). Laboratory searches are in progress, and if they find something persuasive, you won t need me to tell you about it. 

The realization of Bose-Einstein condensates (BEC) and quantum degenerate Fermi gases with cold atoms has been one of the highlights of experimental atomic physics during the last decade [1]. In view of recent progress in the experimental work on the production of cold molecules we expect a similarly spectacular... 

Myatt C, Burt R, Ghrist, Cornell E, Wieman C. (1997) Production of two overlapping Bose-Einstein condensates by sympathetic cooling. Phys. Rev. Lett. 78 (4) 586-589,... 

The trapping of cold neutral atoms is a powerful tool in experimental atomic physics that has made it possible to conduct many fundamental experiments, such as Bose Einstein condensation and the production of Fermi-degenerate quantmn gases. It is therefore one of the most vivid demonstrations of the capabilities inherent in the laser control of atoms. 

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