High Phase-Space Density of Laser-Cooled Molecules in an Optical Lattice

TL;DR

This paper demonstrates efficient laser cooling and trapping of YO molecules in an optical lattice, achieving ultra-cold temperatures and high phase-space density, advancing the control of molecules for quantum applications.

Contribution

It introduces a method for laser cooling molecules in an optical lattice, achieving record low temperatures and high phase-space density for YO molecules.

Findings

Molecules cooled to 6.1 μK in the lattice.

Produced a trapped sample of 1200 molecules.

Achieved a phase-space density of 3.1×10^{-6}.

Abstract

We report laser cooling and trapping of yttrium monoxide (YO) molecules in an optical lattice. We show that gray molasses cooling remains exceptionally efficient for YO molecules inside the lattice with a molecule temperature as low as 6.1(6) $\mu$K. This approach has produced a trapped sample of 1200 molecules, with a peak spatial density of $\sim1.2\times10^{10}$ cm$^{-3}$, and a peak phase-space density of $\sim3.1\times10^{-6}$. By adiabatically ramping down the lattice depth, we cool the molecules further to 1.0(2) $\mu$K, twenty times colder than previously reported for laser-cooled molecules in a trap.