Sisyphus cooling
Encyclopedia
Sisyphus cooling is a mechanism through which atoms can be cooled using laser beams below the temperatures expected to be achieved by Doppler cooling
. It comes about as a result of a polarization gradient created by two counter-propagating laser beams with orthogonal
polarization. Atoms moving through the potential landscape created by the standing wave (created by the interference of the two counter-propagating beams) lose kinetic energy
as they move to a potential maximum, at which point optical pumping
moves them to a lower-energy state, thus losing the potential energy they had.
Repeated cycles of converting kinetic energy to potential energy, then losing potential energy via optical pumping allow the atoms to reach temperatures orders of magnitude below those available through simple Doppler cooling
.
Doppler cooling
Doppler cooling is a mechanism that can be used to trap and cool atoms. The term is sometimes used synonymously with laser cooling, though laser cooling includes other techniques.-History:...
. It comes about as a result of a polarization gradient created by two counter-propagating laser beams with orthogonal
Orthogonality
Orthogonality occurs when two things can vary independently, they are uncorrelated, or they are perpendicular.-Mathematics:In mathematics, two vectors are orthogonal if they are perpendicular, i.e., they form a right angle...
polarization. Atoms moving through the potential landscape created by the standing wave (created by the interference of the two counter-propagating beams) lose kinetic energy
Kinetic energy
The kinetic energy of an object is the energy which 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 acceleration, the body maintains this kinetic energy unless its speed changes...
as they move to a potential maximum, at which point optical pumping
Optical pumping
Optical pumping is a process in which light is used to raise electrons from a lower energy level in an atom or molecule to a higher one. It is commonly used in laser construction, to pump the active laser medium so as to achieve population inversion...
moves them to a lower-energy state, thus losing the potential energy they had.
Repeated cycles of converting kinetic energy to potential energy, then losing potential energy via optical pumping allow the atoms to reach temperatures orders of magnitude below those available through simple Doppler cooling
Doppler cooling
Doppler cooling is a mechanism that can be used to trap and cool atoms. The term is sometimes used synonymously with laser cooling, though laser cooling includes other techniques.-History:...
.