Identification of Deeply Bound Heteronuclear Molecules Using Pulsed Laser Depletion Spectroscopy

TL;DR

This paper demonstrates a new spectroscopic technique using pulsed laser depletion to analyze vibrational states in ultracold heteronuclear NaCs molecules created near dissociation, enabling detailed molecular state characterization.

Contribution

It introduces a novel pulsed laser depletion spectroscopy method applicable to ultracold molecules for vibrational state analysis.

Findings

Identified specific vibrational levels in ultracold NaCs molecules.

Developed a spectroscopic approach covering a broad energy range.

Successfully assigned vibrational quantum numbers to observed states.

Abstract

We demonstrate that a near-dissociation photoassociation resonance can be used to create a deeply bound molecular sample of ultracold NaCs. To probe the resulting vibrational distribution of the sample, we use a new technique that can be applied to any ultracold molecular system. We utilize a tunable pulsed dye laser to produce efficient spectroscopic scans ($\sim700$ cm$^{-1}$ at a time) in which we observe the $1^{1} \Sigma^{+}\rightarrow 2^{1}\Sigma^{+}-2^{3}\Pi$ vibrational progression, as well as the dissociation limit to the Cs 6$^{2}$P$_{3/2}$ asymptote. We assign $1^{1} \Sigma^{+}$$(\emph{v}$ = 4, 5, 6, 11, 19) vibrational levels in our sample.