Quantum Multimode Model of Elastic Scattering from Bose-Einstein Condensates

Abstract

Mean field approximation treats only coherent aspects of the evolution of a Bose-Einstein condensate. However, in many experiments some atoms scatter out of the condensate. We study a semianalytic model of two counterpropagating atomic Gaussian wave packets incorporating the dynamics of incoherent scattering processes. Within the model we can treat processes of the elastic collision of atoms into the initially empty modes, and observe how, with growing occupation, the bosonic enhancement is slowly kicking in. A condition for the bosonic enhancement effect is found in terms of relevant parameters. Scattered atoms form a squeezed state. Not only are we able to calculate the dynamics of mode occupation, but also the full statistics of scattered atoms.

Cold and trapped metastable noble gases

“…The search for efficient non-classical atomic sources is therefore both natural and desirable. There have been many proposals concerning atom pairs, especially the production and observation of individual entangled pairs of atoms through atomic collisions or the breakup of diatomic molecules (Band et al, 2000;Deuar and Drummond, 2007;Duan et al, 2000;Kheruntsyan and Drummond, 2002;Naidon and Masnou-Seeuws, 2006;Norrie et al, 2006;Opatrný and Kurizki, 2001;Pu and Meystre, 2000;Savage et al, 2006;Ziń et al, 2006Ziń et al, , 2005. As emphasized in Duan et al (2000), pair production can be studied in two limits.…”

Collective emission of matter-wave jets from driven Bose–Einstein condensates

“…We derive the theoretical correlation function by calculating the time evolution of the excited, outgoing modes assuming they are initially in the vacuum state and using the Bogoliubov approximation for the condensate [12][13][14][15][16] (see Supplementary material). Our system is particularly amenable to this treatment because the condensate can be considered homogeneous and stationary.…”

Spontaneous Four-Wave Mixing of de Broglie Waves: Beyond Optics

“…The field of atom optics has developed to the point that one can now speak of the beginning of ''quantum-atom optics'' [1] in which atoms are manipulated in ways similar to photons and in which quantum fluctuations and entanglement play an important role. The demonstration of atom pair production [2,3], either from the dissociation of ultracold molecules, a process analogous to parametric downconversion [4-6], or from collisions of Bose-Einstein condensates (BECs) [7][8][9][10], analogous to four-wave mixing (FWM) [11][12][13][14][15][16][17][18][19][20][21], holds considerable promise for generating atomic squeezed states and demonstrating nonlocal Einstein-Podolsky-Rosen (EPR) correlations [4,5,22,23]. In both these systems, atom-atom interactions play the role of the nonlinear medium that allows conversion processes.…”