Alex Cronin Sep 10 Abstract

Atom interferometry studies of atomic structure

Measurements of atomic polarizability, tune-out wavelengths, and van der Waals potentials made with an atom interferometer all serve as benchmark tests for atomic structure calculations. We used a Pritchard-type atom interferometer with phase shifts caused by electric field gradients in order to measure electric polarizabilities of Na, K, and Rb atoms [1]. We reported ratios of static polarizabilities $\alpha_{\textrm{Rb}} / \alpha_{\textrm{Na}}$ = 1.959(5) with 0.3 percent uncertainty. We studied atomic phase shifts due to laser light in order to measure a tune-out wavelength (where there is a root in dynamic polarizability) for potassium atoms of $\lambda_{\textrm{zero}}$ = 768.9712 nm with 1.5 pm uncertainty [2]. Finally, we measured atom-surface interaction potentials (C3 coefficients) with 2 percent precision, which was sufficient to detect the impact of Rb atomic core electrons on van der Waals potentials [3]. These serve as independent benchmarks for atomic structure calculations because polarizability, tune-out wavelengths, and C3 coefficients all depend on different functions of atomic dipole matrix elements. Advances in atom interferometry measurement techniques used for these measurements will be discussed.

[1] Phys Rev A 81, 053607 (2010) [2] Phys. Rev. Lett. 109, 243004 (2012) [3] Phys. Rev. Lett. 105, 233202 (2010)