laser cooling

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The reduction of kinetic energy of atoms or molecules by means of a tunable laser, which, when set at a certain frequency, will cause approaching atoms that absorb photons to lose momentum.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun physics the process of using the force exerted by a laser to reduce the temperature of a gas, or the spread of velocities of a beam of atoms