Study of the correlation effects in Yb^+ and implications for parity violation

TL;DR

This study compares different theoretical approaches to calculate atomic properties of Yb^+ ions, highlighting the importance of correlation effects for accurate predictions relevant to parity violation experiments.

Contribution

It evaluates the accuracy of monovalent and multivalent models for Yb^+ and emphasizes the significance of correlation effects for precise atomic property calculations.

Findings

Monovalent approximation is insufficient for some properties.

Correlation effects significantly influence Yb^+ atomic properties.

Comparison of methods guides future theoretical improvements.

Abstract

Calculation of the energies, magnetic dipole hyperfine structure constants, E1 transition amplitudes between the low-lying states, and nuclear spin-dependent parity-nonconserving amplitudes for the ^2S_{1/2} - ^2D_{3/2,5/2} transitions in ^{171}Yb^+ ion is performed using two different approaches. First, we carried out many-body perturbation theory calculation considering Yb^+ as a monovalent system. Additional all-order calculations are carried out for selected properties. Second, we carried out configuration interaction calculation considering Yb as a 15-electron system and compared the results obtained by two methods. The accuracy of different methods is evaluated. We find that the monovalent description is inadequate for evaluation of some atomic properties due to significant mixing of the one-particle and the hole-two-particle configurations. Performing the calculation by such different approaches allowed us to establish the importance of various correlation effects for Yb^+ atomic properties for future improvement of theoretical precision in this complicated system.