Coherent amplification of beams of atoms inelastically scattered by the Bose-Einstein condensate

The subject of consideration is coherent amplification of a beam of impurity atoms inelastically scattered by a system of ultracold atoms with collectively excited modes. A kinematic model of weak localization of a new type is used that provides a straightforward explanation for this phenomenon and also makes it possible to derive the angular dependences of the scattering intensity. Based on this model, angular and energy criteria for the existence of the new-type weak localization in an ultracold system of atoms (the Bose-Einstein condensate) are determined. Particular emphasis is on how the principle of indistinguishability influences the weak localization of a beam of atoms inelastically scattered by the Bose-Einstein condensate when scattered and condensed atoms are identical.