Quantum noise in stochastic cooling of trapped atoms

Stochastic cooling of trapped atoms consists of the measurement of total momentum of part of the atoms in the trap and its subsequent compensation by giving the atoms a momentum kick. Both operations may be implemented by application of optical (laser) fields. The fraction of atoms affected is determined by the volume where atoms interact with the applied fields, i.e. the optical beam. This study identifies two sources of quantum noise in stochastic cooling that determine the ultimate cooling limit of the method. They appear as heating when considering the change of energy due to a single operation of stochastic cooling.