In our recent work（H. Jing, J. Cheng, and P. Meystre, Phys. Rev. Lett. 99, 133002 （2007））, we studied the constructive interference between two chemical reaction channels in the process of coherent atom-trimer conversion in a repulsive atomic Bose condensate. This interference can be viewed as a double-slit-like interference in quantum degenerate matter-wave chemistry (superchemistry). The constructive interference can lead to a significant enhancement of trimer production, leading to a new technique for coherent assembly and control of ultracold heteronuclear molecules.