Laser-Cooling Atoms to Within micro-Kelvins of Absolute Zero

Jean Dalibard

James M. Kohel, David J. Seidel, Robert J. Thompson +2 more

INTRODUCTION A variety of techniques have been developed over the past two decades for influencing the motion of atomic gases using laser light. These techniques, termed collectively 'laser cooling,' produce samples of atoms with temperatures one millionth of a degree above absolute zero, ushering in a new era of atomic physics. The exquisite control offered by these techniques has made possible measurements of fundamental constants, atomic clocks used in the realization of the SI unit of time, new atom-wave interferometers, and the realization of Bose-Einstein condensation. To understand the impact of gravity on such cold atoms, consider that if the atmosphere were an ideal gas cooled to one micro-Kelvin, it would only extend just 5 microns above the Earth's surface.

Hidekazu Hachisu

G S Mendhe

The ability to cool, manipulate, and trap atoms using laser light has allowed a new, fast developing field to emerge.The term "laser cooling" describes a variety of methods that use one or more laser light fields to interact with atoms and molecules to cool them down to almost absolute zero.The review paper explores the advancements in laser cooling and magnetic trapping methods, focusing on their applications in achieving ultra-cold temperatures for atoms.It discussed various techniques such as Doppler cooling, optical molasses and evaporative cooling, highlighting their roles in advancing atomic clock accuracy and quantum degeneracy research..The paper emphasizes the importance of these methods in achieving temperatures in the nano-kelvin range without cryogenic methods, marking a significant leap in atomic manipulation and study.

Joseph H. Eberly

The past few years have seen remarkable developments in the ability to control atomic motion by optical techniques. Among the key tools that have been developed for this purpose are the techniques of laser cooling, the significance of which was recognized by the award of the 1997 Nobel Prize in Physics to Steven Chu, Claude Cohen-Tannoudji, and William Phillips. These techniques have made it possible to cool atoms to temperatures lower than have been produced in any other physical system - around 10(-8) degrees Kelvin above absolute zero - and to confine those in traps for extended periods of observation.