Coherent decay of Bose-Einstein condensates.

Atomic Bose-Einstein condensates are singular forms of matter with the coherence between constituent atoms as a defining characteristic. Although this viewpoint is increasingly validated through experimental findings, the mechanisms behind the observed losses are still understood with classical recombinant collision arguments between particles within the condensate itself. By incorporating a general interparticle interaction into the Hamiltonian, a coherent decay rate can be obtained, thus providing a direct link between the observed losses and the microscopic two-body parameters. Appearing in the lifetime, the interaction strength, lambda, is expressed as lambda=8 pia/(1-delta), where the small parameter delta is obtained from a fit to experimental loss data. Most importantly, the lowest order rate exhibits a novel density dependence (rho{3/2}) that can be identified in low temperature tests.