# Magic wavelengths of Ca$^{+}$ ion for linearly and circularly polarized light

## TL;DR

This paper calculates magic wavelengths for Ca$^{+}$ ion transitions under linearly and circularly polarized light using relativistic configuration interaction plus core polarization, providing data useful for precision measurements and quantum control.

## Contribution

It presents new calculations of magic wavelengths for Ca$^{+}$ ion transitions, including for circular polarization, and suggests experimental measurements to determine oscillator strength ratios.

## Key findings

- Magic wavelengths for linearly polarized light agree with previous results.
- Additional magic wavelengths are identified for circularly polarized light.
- Measurement near 850 nm can determine oscillator strength ratios.

## Abstract

The dynamic dipole polarizabilities of the low-lying states of Ca$^{+}$ for linearly and circularly polarized light are calculated by using relativistic configuration interaction plus core polarization (RCICP) approach. The magic wavelengths, at which the two levels of the transitions have the same ac Stark shifts, for $4s$-$4p_{j,m}$ and $4s$-$3d_{j,m}$ magnetic sublevels transitions are determined. The present magic wavelengths for linearly polarized light agree with the available results excellently. The polarizability for the circularly polarized light has the scalar, vector and tensor components. The dynamic polarizability is different for each of magnetic sublevels of the atomic state. Additional magic wavelengths have been found for the circularly polarized light. We recommend that the measurement of the magic wavelength near 850 nm for $4s-4p_{\frac32,m=\pm\frac32,\pm\frac12}$ could be able to determine the oscillator strength ratio of $f_{4p_{\frac32} \to 3d_{\frac32}}$ and $f_{4p_{\frac32} \to 3d_{\frac52}}$.