Transition properties of potassium atom

TL;DR

This paper calculates and compares transition properties, polarizabilities, and magic wavelengths of potassium atom states using relativistic many-body methods, providing more precise data and new insights into state-insensitive trapping.

Contribution

It introduces a relativistic all-order method to evaluate transition amplitudes and polarizabilities, including for states without experimental data, and reexamines magic wavelengths for trapping applications.

Findings

More precise static polarizabilities for ground and 4P states.

First theoretical evaluation of polarizabilities for 3D states.

Reexamination of magic wavelengths for trapping potassium atoms.

Abstract

We report here oscillator strengths, transition rates, branching ratios and lifetimes due to allowed transitions in potassium (K) atom. We evaluate electric dipole (E1) amplitudes using an all order relativistic many-body perturbation method. The obtained results are compared with previously available experimental and theoretical studies. Using the E1 matrix elements mentioned above and estimated from the lifetimes of the 4P states, we determine precise values of static and dynamic polarizabilities for the first five low-lying states in the considered atom. The static polarizabilities of the ground and 4P states in the present work are more precise than the available measurements in these states. Only the present work employs relativistic theory to evaluate polarizabilities in the 3D states for which no experimental results are known to compare with. We also reexamine "magic wavelengths" for the $4P_{1/2} \rightarrow 4S$ and $4P_{3/2} \rightarrow 4S$ transitions due to the linearly polarized light which are useful to perform state-insensitive trapping of K atoms.