The Cool Physics of Bose-Einstein Condensation

Carl Wieman

The following article is a written version of the Richtmyer award lecture given to the annual meeting of the American Association of Physics Teachers in January 1996. I discuss the basic idea of Bose–Einstein condensation in a gas and how it has been produced and examined. To cool the atoms to the point of condensation we use laser cooling and trapping, followed by magnetic trapping and evaporative cooling. These techniques are explained, along with the signatures of Bose–Einstein condensation that we observe. I also discuss how very similar laser cooling and trapping techniques have been incorporated into undergraduate laboratory experiments.

Joseph V. Pulé

Adelchi Fabrocini

Z.G. Wang

Since Einstein predicted the phenomenon of Bose-Einstein Condensation in 1924, more physical scientists have tried to realize it, but they didn’t break through until 1995. In this paper, the characteristics and conditions of BEC are introduced first, and then the exploration course is presented. Based on these studied, the realizing techniques of BEC is proposed, including Laser Refrigeration Technique, Ion Trapping of Magnetic Capture, Evaporative Cooling Technology and Measurement Technology of BEC, etc.

Badri Krishnan

S. N. Bose gave a new identity to the quanta of light, introduced into physics by Planck and Einstein, and derived Planck's formula for the radiation spectrum. Chance events led to Einstein's insightful use of Bose's result to build a quantum theory of atomic gases, with the remarkable prediction of a new type of condensation without interactions. Though the spectacular phenomena of superfluidity and superconductivity were identified as the consequences of Bose-Einstein Condensation, the phenomenon in its near pure form, as foresaw by Einstein, was observed 70 years later in atomic gases. The quest for atomic gas BEC was behind much of the developments of laser cooling and trapping of atoms. Since then, the atomic gas BEC has grown into a major research theme and versatile research tool all over the world. I outline the development that made BEC of laser cooled atoms the promised 'Swiss army knife' of laboratory physics, with mentions of some of the examples and applications. My involvement in this field of research at 'home and the world' is briefly reviewed.

Masahito Ueda