# Three-body interaction near a narrow two-body zero crossing

## TL;DR

This paper calculates the effective three-body force for bosons near a narrow two-body zero crossing, revealing how narrow crossings can significantly enhance three-body interactions, with implications for stabilizing dipolar quantum gases.

## Contribution

It provides a detailed theoretical analysis of three-body forces near narrow zero crossings using a two-channel model, highlighting the enhancement effects.

## Key findings

- Three-body force is enhanced near narrow zero crossings.
- The atom-dimer interaction is the main source of three-body forces.
- Enhanced three-body interactions can stabilize dipolar atomic systems.

## Abstract

We calculate the effective three-body force for bosons interacting with each other by a two-body potential tuned to a narrow zero crossing in any dimension. We use the standard two-channel model parametrized by the background atom-atom interaction strength, the amplitude of the open-channel to closed-channel coupling, and the atom-dimer interaction strength. The three-body force originates from the atom-dimer interaction, but it can be dramatically enhanced for narrow crossings, i.e., for small atom-dimer conversion amplitudes. This effect can be used to stabilize quasi-two-dimensional dipolar atoms and molecules.