Broad Feshbach resonances in ultracold alkali-metal systems

TL;DR

This paper predicts and characterizes new broad Feshbach resonances in alkali-metal systems using quantum-defect theory, providing guidance for experimental studies of high-partial-wave interactions.

Contribution

It introduces a comprehensive theoretical search for broad Feshbach resonances across all alkali-metal pairs, identifying stable high-partial-wave resonances and their properties.

Findings

Predicted new broad s-, p-, and d-wave Feshbach resonances.

Found no broad p- or d-wave resonances free of two-body loss in fermionic alkali atoms up to 1000 G.

Provided detailed characterization of these resonances for experimental guidance.

Abstract

A comprehensive search for "broad" Feshbach resonances (FRs) in all possible combinations of stable alkali-metal atoms is carried out, using a multi-channel quantum-defect theory assisted by the analytic wave functions for a long-range van-der-Waals potential. A number of new "broad" $s$-, $p$- and $d$-wave FRs in the lowest-energy scattering channels, which are stable against two-body dipolar spin-flip loss, are predicted and characterized. Our results also show that "broad" FRs of $p$- or $d$-wave type that are free of two-body loss do not exist between fermionic alkali-metal atoms for magnetic field up to 1000\,G. These findings constitute helpful guidance on efforts towards experimental study of high-partial-wave coupling induced many-body physics.