Neutral Atom Traps for Bose-Einstein Condensation

Abstract

Optical and magnetic trapping of neutral atoms, to produce ultracold and dense samples of atomic vapours, is a new phenomenon in physics that has potential for use in many areas of research. Observation of Bose-Einstein condensation (BEC) in dilute vapours of alkali atoms [1–4] is one of the fascinating applications of these atomic trapping and cooling techniques. For BEC, one must produce a sample of bosonic particles whose thermal de Broglie wavelength exceeds the mean inter-atomic separation. Under this situation the Bose statistics favours the condensation of all the atoms into a single quantum state of the system [5]. Clearly such a phase transition can be observed only at ultra low temperatures and relatively high densities of bosonic particles. Fuelled by the search for high densities and very low temperatures of atomic vapours, last few years have seen a flurry of activities in demonstrating a variety of neutral atom traps [6, 7]. These have made it possible to obtain dense samples of atomic systems at unprecedented low temperatures for the observation of the collective quantum effects. Other applications of these neutral atom traps include very high resolution spectroscopy, metrology, nonlinear optics, atom optics and “non-accelerator” particle physics [8].