Multi-channel modeling and two photon coherent transfer paths in NaK

TL;DR

This paper investigates pathways for creating ultracold NaK molecules in their ground state, combining multi-channel theoretical analysis with experimental demonstration of coherent transfer techniques.

Contribution

It provides a detailed multi-channel analysis of NaK's electronic states and demonstrates a STIRAP transfer method from Feshbach to ground state molecules.

Findings

Identification of viable two-photon transfer pathways

Successful experimental demonstration of STIRAP transfer

Enhanced understanding of NaK electronic state manifold

Abstract

We explore possible pathways for the creation of ultracold polar NaK molecules in their absolute electronic and rovibrational ground state starting from ultracold Feshbach molecules. In particular, we present a multi-channel analysis of the electronic ground and K(4p)+Na(3s) excited state manifold of NaK, analyze the spin character of both the Feshbach molecular state and the electronically excited intermediate states and discuss possible coherent two-photon transfer paths from Feshbach molecules to rovibronic ground state molecules. The theoretical study is complemented by the demonstration of STIRAP transfer from the X^1\Sigma^+ (v=0) state to the a^3\Sigma^+ manifold on a molecular beam experiment.