Dressed ion-pair states of an ultralong-range Rydberg molecule

TL;DR

This paper predicts a new class of ultralong-range Rydberg molecules with unique vibrational spectra, modeled by a dressed ion-pair approach, revealing exotic properties and a surprisingly small Rydberg constant.

Contribution

It introduces a dressed ion-pair model that accurately predicts properties of these exotic ultralong-range Rydberg molecules and heavy Rydberg states.

Findings

Existence of a universal class of ultralong-range Rydberg molecular states.

Vibrational spectra form trimmed Rydberg series.

Rydberg constant smaller than R_/2 due to small effective charge.

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 $R_\infty/2$.