At temperatures a few billionths of a degree above absolute zero atoms act more like waves than particles. For certain types of atoms (bosons) a phase transition can be observed at cold temperatures which leads to a novel form of matter known as a Bose condensate. In this state all the atoms occupy the same quantum state, and behave in a coherent fashion. First observed in 1995, Bose-Einstein condensation (BEC) of dilute gases was the subject of the 2001 Nobel Prize in physics.

To obtain a Bose condensate it is necessary to cool atoms to the extent that their associated De Broglie wavelengths overlap with those of their neighbors. In general, this requires the production of exceptionally cold temperatures, less than a millionth of a degree above absolute zero.

We have pursued an all-optical approach to BEC. We start with a two-dimensional magneto-optical trap, which produces a cold beam of Rubidium atoms and can load as many as 500 million atoms per second into a conventional magneto-optical trap held in an ultra-high vacuum chamber. These atoms are collected and then transferred into a purely optical trap formed by a focused CO₂ laser beam. The intensity of this laser beam is then turned down slowly, allowing the hottest atoms to escape. The remaining atoms re-equilibrate at lower temperatures, a process known as evaporative cooling. Bose condensation is observed to occur at temperatures about 150 billionths of a degree above absolute zero. Pure condensates with as many as 20000 atoms have been produced to date.

We are particularly interested in developing methods to produce very large condensates via all optical means, and as well at studying the effects of gravity on the production and behavior of condensates. Additionally we will be using our Bose condensates as a source for atom interferometer-based sensors, such as a gravity gradiometer. Our long-term interest is in developing new quantum technologies that will enable a new generation of sensors, capable of detecting a variety of physical phenomena, from gravitational forces to magnetic fields, with unprecedented sensitivity.