Accurate determination of quadrupole polarizabilities of the excited states of alkali-metal atoms

TL;DR

This paper accurately calculates the electric quadrupole polarizabilities of excited alkali-metal atom states, providing new data to aid precision measurements and validating methods through comparison with known ground state values.

Contribution

It presents the first accurate estimates of E2 polarizabilities for excited states of all alkali-metal atoms, including those previously unknown.

Findings

Ground state E2 polarizabilities agree with literature.

Estimated excited state E2 polarizabilities are consistent and accurate.

Results can guide future precision measurements.

Abstract

The scalar and tensor components of the electric quadrupole (E2) polarizabilities of the first two excited states of all the alkali-metal atoms are determined. To validate the calculations, we have evaluated the ground state E2 polarizabilities of these atoms and compared them with the literature values. We could not find the ground state E2 polarizability value for Fr in the literature to compare with our result. The dominant parts of these quantities are estimated by combining the precisely calculated E2 transition matrix elements of many low-lying transitions with the experimental energies, while the other contributions are estimated using lower-order methods. Our estimated values for the ground states of the above atoms are in good agreement with the literature values suggesting that our estimated E2 polarizabilities for the excited states of the alkali atoms, which were not known earlier except for the Li atom, are also quite accurate. These reported E2 polarizabilities could be useful in guiding many precision measurements in the alkali atoms.