# Microwave shielding of ultracold polar molecules with imperfectly circular polarization

## TL;DR

This paper explores how microwave radiation with near-circular polarization can create a repulsive shield to prevent collisional losses in ultracold polar molecules, using coupled-channels calculations.

## Contribution

It demonstrates that effective shielding is possible with elliptical polarization close to circular, expanding the understanding of polarization requirements for molecular shielding.

## Key findings

- Effective shielding requires predominantly circular polarization.
- Shielding can still be achieved with approximately 90% circular polarization.
- Coupled-channels calculations confirm the feasibility of microwave shielding.

## Abstract

We investigate the use of microwave radiation to produce a repulsive shield between pairs of ultracold polar molecules and prevent collisional losses that occur when molecular pairs reach short range. We carry out coupled-channels calculations on RbCs+RbCs and CaF+CaF collisions in microwave fields. We show that effective shielding requires predominantly circular polarization, but can still be achieved with elliptical polarization that is around 90% circular.