Stark deceleration of lithium hydride molecules

TL;DR

This paper reports the production, deceleration, and analysis of cold lithium hydride molecules using Stark deceleration, with detailed experimental and simulation comparisons to optimize future trapping and cooling.

Contribution

It introduces a method for decelerating LiH molecules with a 100-stage Stark decelerator and compares two deceleration modes, supported by detailed simulations.

Findings

Successful deceleration of LiH molecules from 420m/s to 53m/s.

Good agreement between experimental data and simulations.

Insights into the source size and transition probabilities of molecules.

Abstract

We describe the production of cold, slow-moving LiH molecules. The molecules are produced in the ground state using laser ablation and supersonic expansion, and 68% of the population is transferred to the rotationally excited state using narrowband radiation at the rotational frequency of 444GHz. The molecules are then decelerated from 420m/s to 53m/s using a 100 stage Stark decelerator. We demonstrate and compare two different deceleration modes, one where every stage is used for deceleration, and another where every third stage decelerates and the intervening stages are used to focus the molecules more effectively. We compare our experimental data to the results of simulations and find good agreement. These simulations include the velocity dependence of the detection efficiency and the probability of transitions between the weak-field seeking and strong-field seeking quantum states. Together, the experimental and simulated data provide information about the spatial extent of the source of molecules. We consider the prospects for future trapping and sympathetic cooling experiments.