Stark effect of the cesium ground state: electric tensor polarizability and shift of the clock transition frequency

TL;DR

This paper provides a detailed theoretical analysis of the Stark effect in cesium's ground state, accurately calculating tensor polarizability and clock transition shifts, resolving longstanding discrepancies with experimental data.

Contribution

It introduces a third-order perturbation theory approach including hyperfine interactions, yielding new, accurate values for cesium's tensor polarizability and Stark shift.

Findings

Tensor polarizability aligns with experimental data

Stark shift agrees with recent measurements

Contradicts traditional values used in frequency standards

Abstract

We present a theoretical analysis of the Stark effect in the hyperfine structure of the cesium ground-state. We have used third order perturbation theory, including diagonal and off-diagonal hyperfine interactions, and have identified terms which were not considered in earlier treatments. A numerical evaluation using perturbing levels up to n=18 yields new values for the tensor polarizability $\alpha_2(6S_{1/2})$ and for the Stark shift of the clock transition frequency in cesium. The polarizabilities are in good agreement with experimental values, thereby removing a 40-year-old discrepancy. The clock shift value is in excellent agreement with a recent measurement, but in contradiction with the commonly accepted value used to correct the black-body shift of primary frequency standards.