Experimental observation of magic-wavelength behavior in optical lattice-trapped $^{87}$Rb

TL;DR

This paper demonstrates the experimental cancellation of differential ac Stark shifts in trapped $^{87}$Rb atoms' microwave hyperfine transition by tuning wavelength, polarization, and magnetic field, enhancing precision in atomic control.

Contribution

It introduces a novel method to achieve ac Stark shift cancellation for microwave transitions in alkali atoms, which was previously thought impossible.

Findings

Successful cancellation of differential ac Stark shift in $^{87}$Rb

Identification of specific conditions for shift cancellation

Implications for improved atomic clock precision

Abstract

We demonstrate the cancellation of the differential ac Stark shift of the microwave hyperfine clock transition in trapped $^{87}$Rb atoms. Recent progress in metrology exploits so-called "magic wavelengths," whereby an atomic ensemble can be trapped with laser light whose wavelength is chosen so that both levels of an optical atomic transition experience identical ac Stark shifts. Similar magic-wavelength techniques are not possible for the microwave hyperfine transitions in the alkalis, due to their simple electronic structure. We show, however, that ac Stark shift cancellation is indeed achievable for certain values of wavelength, polarization, and magnetic field. The cancellation comes at the expense of a small magnetic-field sensitivity. The technique demonstrated here has implications for experiments involving the precise control of optically-trapped neutral atoms.