Generalized local frame transformation theory for ultralong-range Rydberg molecules

TL;DR

This paper introduces a generalized local frame transformation theory for ultralong-range Rydberg molecules, providing analytical tools for potential energy calculations and molecular process analysis, validated through Rb and Sr molecule studies.

Contribution

The work develops a pseudopotential-free, analytical framework for Rydberg molecules, enhancing accuracy and physical insight compared to existing methods.

Findings

Accurate potential energy curves for Rb*--Rb molecules

Re-analysis of Sr*--Sr vibrational spectra with improved insights

Validation against state-of-the-art approaches

Abstract

A detailed theoretical framework for highly excited Rydberg molecules is developed based on the generalized local frame transformation. Our approach avoids the use of pseudopotentials and yields analytical expressions for the body-frame reaction matrix. The latter is used to obtain the molecular potential energy curves, but equally it can be employed for photodissociation, photoionization, or other processes. To illustrate the reliability and accuracy of our treatment we consider the Rb$^*-$Rb Rydberg molecule and compare our treatment with state-of-the-art alternative approaches. As a second application, the present formalism is used to re-analyze the vibrational spectra of Sr$^*-$Sr molecules, providing additional physical insight into their properties and a comparison of our results with corresponding measurements.