Dressed Ion-Pair States of an Ultralong-Range Rydberg Molecule

F Robicheaux,P Giannakeas,Matthew T Eiles,Jan M Rost

doi:10.1103/physrevlett.125.123401

Abstract

We predict the existence of a universal class of ultralong-range Rydberg molecular states whose vibrational spectra form trimmed Rydberg series. A dressed ion-pair model captures the physical origin of these exotic molecules, accurately predicts their properties, and reveals features of ultralong-range Rydberg molecules and heavy Rydberg states with a surprisingly small Rydberg constant. The latter is determined by the small effective charge of the dressed anion, which outweighs the contribution of the molecule's large reduced mass. This renders these molecules the only known few-body systems to have a Rydberg constant smaller than R_{∞}/2.

Highlights

The richness of Rydberg physics is highlighted by two exotic molecular systems which have attracted recent interest: ultralong-range Rydberg molecules (ULRM) and heavy Rydberg states (HRS)
The experimental observation of ULRMs [5,6,7] has led to their use in many diverse applications, e.g., as probes of chargeneutral interactions [8,9,10,11,12,13] or as impurities embedded in a many-body bath [14,15,16,17,18,19,20,21,22,23,24]
In this Letter, we predict a class of highly excited molecular states which realize properties of HRS on the electronic energy scale of ULRMs, combining both concepts

Summary

Introduction

The richness of Rydberg physics is highlighted by two exotic molecular systems which have attracted recent interest: ultralong-range Rydberg molecules (ULRM) and heavy Rydberg states (HRS). ULRMs exist because the Rydberg electron accumulates an appreciable phase shift as it scatters off of the perturber, which in turn produces an energy shift proportional to the S-wave scattering length [25,26]. The inclusion of higher partial waves (L ≥ 2) in the e − B interaction yields a hierarchy of “truncated Coulomb” potential energy curves (PECs) governing the vibrational motion associated with every degenerate electronic Rydberg manifold, labeled by n.

Results

Conclusion