Millimeter-wave spectroscopy of neutral mercury in Rydberg F states

Abstract

To our knowledge, this is the first study to report the quantum defects of ${}^1{F}_3$ and ${}^3{F}_3$ highly-excited states of neutral mercury. The frequencies of 36 measured two-photon Rydberg–Rydberg $6snf{F}_J^{}{}^{1,3}\to 6s(n+1)f{F}_J^{}{}^{1,3}$ transitions were fitted by Rydberg–Ritz formula to derive the quantum defect values. The transitions were driven from Rydberg singlet and triplet $F$ levels selectively populated via two-step laser excitation scheme. The observed transitions spanned the frequency range 49–81 GHz and the range of the principal quantum number $n=35-42.$ The details of the experiment are presented.

Keywords:

• Laser excitation
• mercury atom
• millimeter-wave spectroscopy
• pulse-field ionization
• Rydberg atom

Acknowledgements

We are grateful to anonymous referees whose comments helped us to improve the manuscript. We also thank Dr. V. Efremov for his help in data analysis.