Ion-assisted ground-state cooling of a trapped polar molecule

TL;DR

This paper presents a novel scheme for cooling polar molecules in an optical lattice by using laser-cooled ions and parametric resonance, enabling ground-state cooling of molecular translational motion.

Contribution

It introduces a new ion-assisted cooling method utilizing parametric resonance to achieve ground-state cooling of trapped polar molecules.

Findings

Analytical solution for small modulation regime

Final molecular energy depends on modulation amplitude

Cooling rate varies with parametric modulation strength

Abstract

We propose and analyze a scheme for sympathetic cooling of the translational motion of polar molecules in an optical lattice, interacting one by one with laser-cooled ions in a radio-frequency trap. The energy gap between the excitation spectra of the particles in their respective trapping potentials is bridged by means of a parametric resonance, provided by the additional modulation of the RF field. We analyze two scenarios: simultaneous laser cooling and energy exchange between the ion and the molecule, and a scheme when these two processes take place separately. We calculate the lowest final energy of the molecule and the cooling rate depending on the amplitude of the parametric modulation. For small parametric modulation, the dynamics can be solved analytically within the rotating wave approximation.