Directional "superradiant" collisions: bosonic amplification of atom pairs emitted from an elongated Bose-Einstein condensate.
We study spontaneous directionality in the bosonic amplification of atom pairs emitted from an elongated Bose-Einstein condensate, an effect analogous to superradiant emission of atom-photon pairs. Using a simplified model, we make analytic predictions regarding directional effects for both atom-atom and atom-photon emission. These are confirmed by numerical mean-field simulations, demonstrating the feasibility of nearly perfect directional emission along the condensate axis. The dependence of the emission angle on the pump strength for atom-atom pairs is significantly different than for atom-photon pairs.
Vardi
A
A
Institute for Theoretical Atomic and Molecular Physics, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA.
Moore
M G
MG