Sympathetic cooling is a process in which particles of one type cool particles of another type. Typically, atomic ions that can be directly laser cooled are used to cool nearby ions or atoms, by way of their mutual

Coulomb interaction Coulomb's inverse-square law, or simply Coulomb's law, is an experimental law of physics that quantifies the amount of force between two stationary, electrically charged particles. The electric force between charged bodies at rest is convention ...

. This technique is used to cool ions and atoms that cannot be cooled directly by laser cooling, which includes most molecular ion species, especially large organic molecules. However, sympathetic cooling is most efficient when the mass/charge ratios of the sympathetic- and laser-cooled ions are similar. The cooling of neutral atoms in this manner was first demonstrated by Christopher Myatt et al. in 1997. * Here, a technique with electric and magnetic fields were used, where atoms with spin in one direction were more weakly confined than those with spin in the opposite direction. The weakly confined atoms with a high

kinetic energy In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acc ...

were allowed to more easily escape, lowering the total kinetic energy, resulting in a cooling of the strongly confined atoms. Myatt et al. also showed the utility of their version of sympathetic cooling for the creation of

Bose–Einstein condensate In condensed matter physics, a Bose–Einstein condensate (BEC) is a state of matter that is typically formed when a gas of bosons at very low densities is cooled to temperatures very close to absolute zero (−273.15 °C or −459.6 ...

References

Atomic, molecular, and optical physics Cooling technology Thermodynamics {{nuclear-stub