Position and state control of single atoms using optical tweezers

A small known number of cesium atoms is loaded from a magneto-optical trap into a far detuned, standing wave optical dipole trap. This trap is made of two counter-propagating Nd:YAG laser beams (/spl lambda/= 1064 nm) which give rise to a chain of potential wells with a depth of about 1 mK and an axial spacing of 532 nm. By fitting the axial intensity distribution with a Gaussian function, the positions of the individual atoms are determined automatically with a precision of 100 nm rms, mainly limited by photon statistics.