Communications in Theoretical Physics

Atom-dimer scattering and collisional stability in two-dimensional quantum gases

Yirong Wang, Jiaqi Yi, 高奎意, Wei Zhang

Published May 15, 2026• 0 citations

Abstract

Abstract The characterization of few-body interactions is fundamental for understanding the properties and collisional stability of ultracold quantum gases in reduced dimensions. In this work, we theoretically investigate the atom-dimer scattering and three-body recombination processes in a two-dimensional quantum gas. By generalizing the Skorniakov–Ter-Martirosian equations to two dimensions, we obtain the exact atom-dimer scattering amplitude and systematically evaluate the validity of common theoretical approximations, revealing a distinct feature of two-dimensional (2D) collisions: while mean-field theory fails rapidly with increasing interaction strength, the single-pole approximation remains remarkably accurate across a broad interaction regime. Furthermore, we extend our exact framework to non-zero incident momenta to calculate the three-body recombination rate. Our results demonstrate that the lifetime of the 2D quantum gas exhibits a power-law dependence on the 2D gas parameter n a 2D 2 with an exponent of approximately − 2.45 , showing a significant reduction in stability as interactions are enhanced. This study bridges the gap between exact few-body theory and practical many-body approximations, offering a robust benchmark for predicting the stability of cold atomic mixtures and guiding future experimental explorations of universal few-body physics in highly controllable 2D environments.

DOI: 10.1088/1572-9494/ae6e31

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