Cruising through molecular bound state manifolds with radio frequency

TL;DR

This paper presents a simple, efficient radio-frequency method for transferring ultracold molecules between quantum states via Zeeman tuning and avoided crossings, enabling navigation through complex molecular state manifolds.

Contribution

It introduces a general RF-based transfer technique for ultracold molecules that simplifies state manipulation compared to optical Raman methods.

Findings

Achieved over 99% transfer efficiency between quantum states.

Demonstrated successively transporting molecules through multiple quantum states.

Developed a high-precision spectroscopy method for level crossing investigation.

Abstract

The emerging field of ultracold molecules with their rich internal structure is currently attracting a lot of interest. Various methods have been developed to produce ultracold molecules in pre-set quantum states. For future experiments it will be important to efficiently transfer these molecules from their initial quantum state to other quantum states of interest. Optical Raman schemes are excellent tools for transfer, but can be involved in terms of equipment, laser stabilization and finding the right transitions. Here we demonstrate a very general and simple way for transfer of molecules from one quantum state to a neighboring quantum state with better than 99% efficiency. The scheme is based on Zeeman tuning the molecular state to avoided level crossings where radio-frequency transitions can then be carried out. By repeating this process at different crossings, molecules can be successively transported through a large manifold of quantum states. As an important spin-off of our experiments, we demonstrate a high-precision spectroscopy method for investigating level crossings.