Quasiclassical theory of quantum defect and spectrum of highly excited rubidium atoms

TL;DR

This paper develops a modified quasiclassical approach to accurately model the spectrum of highly excited rubidium atoms, resolving discrepancies between previous calculations and experimental measurements.

Contribution

It introduces a modified effective potential within a WKB framework to improve the theoretical prediction of Rydberg state spectra in rubidium.

Findings

Achieves very good agreement with experimental spectroscopic data

Resolves discrepancies between variational calculations and measurements

Provides a refined method for modeling Rydberg spectra

Abstract

We report on a significant discrepancy between recently published highly accurate variational calculations and precise measurements of the spectrum of Rydberg states in $^{87}$Rb on the energy scale of fine splitting. Introducing a modified effective single-electron potential we determine the spectrum of the outermost bound electron from a standard WKB approach. Overall very good agreement with precise spectroscopic data is obtained.