Influence of the energy-band structure on ultracold reactive processes in lattices

TL;DR

This paper presents a theoretical study of ultracold reactive collisions in quasi-one-dimensional optical lattices, emphasizing how energy-band structures influence reaction dynamics and the importance of momentum-dependent coupling in effective models.

Contribution

It introduces a model that accounts for excited energy bands and momentum-dependent coupling, providing insights for accurate tight-binding descriptions of ultracold reactions.

Findings

Energy-band structure significantly affects reactive processes.

Momentum dependence of coupling constants is crucial even in deep lattices.

The model is adaptable for rigorous close-coupled calculations.

Abstract

We study theoretically ultracold collisions in quasi one-dimensional optical traps for bosonic and fermionic reactive molecules in the presence of a periodic potential along the trap axis. Elastic, reactive, and umklapp processes due to non-conservation of the center of mass motion are investigated for parameters of relevant experimental interest. The model naturally keeps into account the effect of excited energy bands and is particularly suited for being adapted to rigorous close-coupled calculations. Our formalism shows that a correct derivation of the parameters in tight-binding effective models must include the strong momentum dependence of the coupling constant we predict even for deep lattices.