Universal three-body recombination via resonant d-wave interactions

TL;DR

This paper investigates a universal three-body recombination process involving resonant d-wave interactions in ultracold bosonic gases, revealing a new three-body state near the d-wave dimer formation threshold.

Contribution

It extends Efimov physics to include d-wave interactions, identifying a universal three-body state associated with d-wave dimers and providing improved computational methods.

Findings

Discovery of a universal three-body state near the d-wave dimer threshold at a ≈ 1.09 r_vdW.

Enhanced three-body recombination signatures linked to the d-wave state.

Calculation and analysis of effective potential curves for understanding recombination dynamics.

Abstract

For a system of three identical bosons interacting via short-range forces, when two of the atoms are about to form a two-body s-wave dimer, there exists an infinite number of three-body bound states. This effect is the well-known Efimov effect. These three-body states (Efimov states) are found to be universal for ultracold atomic gases and the lowest Efimov state crosses the three-body break-up threshold when the s-wave two-body scattering length is $a \approx -9.73 r_{\rm vdW}$, $r_{\rm vdW}$ being the van der Waals length. This article focuses on a generalized version of this Efimov scenario, where two of the atoms are about to form a two-body d-wave dimer, which leads to strong d-wave interactions. In a recent paper [B. Gao, Phys. Rev. A. {\bf 62}, 050702(R) (2000)], Bo Gao has predicted that for broad resonances the d-wave dimer is always formed near $a \approx 0.956 r_{\rm vdW}$. Here we find that a single universal three-body state associated with the d-wave dimer is also formed near the three-body break-up threshold at $a \approx 1.09 r_{\rm vdW}$ and its signature can be found through enhancement of the three-body recombination. The three-body effective potential curves that are crucial for understanding the recombination dynamics are also calculated and analyzed. An improved method to calculate the couplings, effective potential curves, and recombination rate coefficients is presented.