# Equilibrium trapping of cold atoms using dipole and radiative forces in an optical trap

## TL;DR

This paper introduces a novel optical trapping method for cold atoms that combines dipole and radiative forces near resonance, achieving stable trapping conditions that depend on laser detuning.

## Contribution

The study demonstrates a new stable trapping technique using near-resonant optical forces, expanding the understanding of atom trapping mechanisms.

## Key findings

- Stable trapping achieved with near-resonant optical forces.
- Trap position depends on laser detuning, not intensity.
- Differences in equilibrium positions relate to force balance changes.

## Abstract

We report on highly effective trapping of cold atoms by a new method for a stable single optical trap in the near-optical resonant regime. An optical trap with the near-optical resonance condition consists of not only the dipole but also the radiative forces, while a trap using a far-off resonance dominates only the dipole force. We estimate a near-optical resonant trap for ultracold rubidium atoms in the range between -0.373 and -2.23 THz from the resonance. The time dependence of the trapped atoms indicates some difference of the stable center-of-mass positions in the near-optical resonant trap, and also indicates that the differences are caused by the change of the equilibrium condition of the optical dipole and radiative forces. A stable position depends only on laser detuning due to the change in the radiative force; however, the position is ineffective against the change in the laser intensity, which results in a change in the radiative force.