Ultracold Three-body Recombination in Two Dimensions

TL;DR

This paper investigates three-body recombination in two-dimensional quantum systems, deriving formulas and analyzing how long-range effects influence recombination rates and universal states for bosons and fermions.

Contribution

It provides semi-analytical formulas for recombination rates in 2D and highlights the significance of long-range corrections, extending understanding beyond previous 3D studies.

Findings

Long-range corrections significantly alter recombination rates.

Recombination is suppressed in 2D compared to 3D.

Universal three-boson states approach predictions slowly with increasing scattering length.

Abstract

We study three-body recombination in two dimensions for systems interacting via short-range two-body interactions in the regime of large scattering lengths. Using the adiabatic hyperspherical representation, we derive semi-analytical formulas for three-body recombination in both weakly and deeply bound diatom states. Our results demonstrate the importance of long-range corrections to the three-body potentials by showing how they alter the low-energy and scattering length dependence of the recombination rate for both bosonic and fermionic systems, which exhibit suppressed recombination if compared to the three-dimensional case. We verify these results through numerical calculations of recombination for systems with finite-range interactions and supporting a few two-body bound states. We also study finite-range effects for the energies of the universal three-identical-bosons states and found a slow approach to universal predictions as a function of the scattering length.