A Maxwell's demon in the generation of an intense and slow guided beam
  We analyze quantitatively the generation of a continuous beam of atoms by the periodic injection of individual packets in a guide, followed by their overlapping. We show that slowing the packets using a moving mirror before their overlapping enables an optimal gain on the phase space density of the generated beam. This is interpreted as a Maxwell's demon type strategy as the experimentalist exploits the information on the position and velocity of the center of mass of each packet. 
Ga\"el Reinaudi (LKB - Lhomond), David Guery-Odelin (LKB - Lhomond,   LCAR)