laser cooling

A photo of laser-cooled lithium atoms. The bright blob corresponds to roughly 7 billion lithium atoms scattering the 671 nm light used to laser cool them to a temperature of a few hundred microkelvin. The cloud is about 5 mm in extent. A window of the vacuum system where the lithium is trapped along with supporting optics can be seen in the foreground. The lithium atoms are then evaporatively cooled to make a Bose–Einstein condensate. Laser-cooled lithium atoms being loaded into a magneto-optical trap from a Zeeman slower

Laser cooling includes several techniques where atoms, molecules, and small mechanical systems are cooled with laser light. The directed energy of lasers is often associated with heating materials, e.g. laser cutting, so it can be counterintuitive that laser cooling often results in sample temperatures approaching absolute zero. It is routinely used in atomic physics experiments where the laser-cooled atoms are manipulated and measured. It is also used in technologies, such as atom-based quantum computing architectures.