Measurement of atomic polarizabilities using Floquet spectroscopy

Abstract

The complex network of Floquet states that results from an application of an external ac electric field to a collection of atoms is investigated. It is shown that precision dc Stark spectroscopy can reveal the details of the quasienergy states, Floquet states, spawned by the application of a rf field. Transitions to the Floquet sidebands of quadratic (dc) Stark states are found to have absorption intensities in good agreement with theory. This combination of dc and ac fields applied to atoms, Floquet spectroscopy, is then used to determine accurately the scalar and tensor polarizabilities of the 65 $^{2}\mathrm{P}$ state of sodium. Deviations from quadratic behavior are investigated as well as the relationship of our measured polarizability to previous measurements at lower principal quantum numbers.