In the last decades techniques for optical trapping at the atomic scale have flourished. Precise control of the light-matter mechanical coupling has enabled trapping and cooling of neutral atoms, ions and molecules, reaching ever lower temperatures, as shown in Fig. 24.1. This tremendous progress has been recognised with the award of Nobel prizes on three occasions: for laser cooling and trapping (1997), for the realisation of Bose-Einstein condensation of neutral atoms (2001), and for the ma- nipulation of individual quantum systems (2012). The purpose of this Chapter is to present a brief overview of the fundamental concepts in this vast research field, including a description of Doppler and sub-Doppler cooling processes, atom trapping techniques, Bose-Einstein condensation and optical lattices, with particular attention to techniques that make use of optical dipole forces as are used in optical tweezers for microscopic particles.
24.1 Laser cooling and optical molasses
24.2 Atom trapping
24.3 Optical dipole traps for cold atoms
24.4 The path to quantum degeneracy
24.5 Bose–Einstein condensation
24.6 Evaporative cooling and Bose–Einstein condensation in dipole traps
24.7 Holographic optical traps for cold atoms
24.8 Optical lattices
24.9 Further reading
References