Dipole transition strengths in Ba${}^{+}$ from Rydberg fine-structure measurements in Ba and Ba${}^{+}$

Dipole transition strengths in Ba $^{+}$ from Rydberg fine-structure measurements in Ba and Ba $^{+}$

Shannon L. Woods, M. E. Hanni, S. R. Lundeen, and Erica L. Snow

Phys. Rev. A 82, 012506 – Published 12 July 2010

Abstract

The fine structure of high- $L$ $n$ $=$ $19$ and $20$ Rydberg states of Ba $^{+}$ has been measured precisely using the resonant excitation Stark ionization spectroscopy technique, allowing for a determination of the Ba $^{2 +}$ polarizability: $α_{D}$ (Ba $^{2 +}$ ) $=$ $10.75 (10)$ a.u. This result, in combination with an improved model of the $K$ splittings in Ba Rydberg levels, allows for a more precise determination of the Ba $^{+}$ dipole transition strengths connecting the $6$ $^{2} S_{1 / 2}$ ground state to the $6$ $^{2} P_{1 / 2}$ and $6$ $^{2} P_{3 / 2}$ excited states. The results, in atomic units, are $〈$ $6$ $^{2} S_{1 / 2} | | D | | 6^{2} P_{1 / 2} 〉$ $=$ $3.3251 (21)$ and $〈$ 6 $^{2} S_{1 / 2} | | D | | 6^{2} P_{3 / 2} 〉$ $=$ $4.7017 (27)$ .