Observation of individual neutral atoms in magnetic and magneto-optical traps

Abstract

We have identified and photographed individual cesium atoms in a magnetooptical trap with steep magnetic gradients. By switching off the trapping light fields, single atoms were released to a bound state of the magnetic potential. A storage time of 38 s was measured for purely magnetic trapping, whereas a storage time of 147 s was observed in the corresponding magneto-optical trap.

Bose-Einstein condensate in a box

“…The cloud is relatively uniform which is not possible without compensation. The small atom numbers are cross-checked with a single atom counting system [17,18] which allows for independent verification of atom number. Our atom counting setup has been integrated as to allow for atoms to be transferred from the optical trap into a small magneto-optical trap (MOT) so they may be accurately counted by fluorescence.…”

Continued imaging of the transport of a single neutral atom

“…A specially designed six-beam magneto-optical trap (MOT) [7] serves as a source of cold neutral cesium atoms. A high magnetic field gradient of 340 G/cm localizes the atoms to a region of d MOT = 12 µm in diameter.…”

An objective lens for efficient fluorescence detection of single atoms

“…Our experimental requirement is the efficient collection of fluorescence light from single atoms in a magnetooptical trap (MOT) [3] inside a vacuum cell, which itself is situated between two magnetic coils. This results in the following typical requirements for an objective used for single atom experiments:…”