Absolute and ratio measurements of the polarizability of Na, K, and Rb with an atom interferometer

Abstract

We measured the ground-state electric-dipole polarizability of sodium, potassium, and rubidium using a Mach-Zehnder atom interferometer with an electric-field gradient. We find ${\alpha }_{\mathrm{Na}}=24.11(2){}_{\mathrm{stat}}(18){}_{\mathrm{sys}}\times {10}^{-24}{\mathrm{cm}}^3$, ${\alpha }_{\mathrm{K}}=43.06(14)(33)$, and ${\alpha }_{\mathrm{Rb}}=47.24(12)(42)$. Since these measurements were all performed in the same apparatus and subject to the same systematic errors, we can present polarizability ratios with $0.3\%$ uncertainty. We find ${\alpha }_{\mathrm{Rb}}/{\alpha }_{\mathrm{Na}}=1.959(5)$, ${\alpha }_{\mathrm{K}}/{\alpha }_{\mathrm{Na}}=1.786(6)$, and ${\alpha }_{\mathrm{Rb}}/{\alpha }_{\mathrm{K}}=1.097(5)$. We combine our ratio measurements with the higher-precision measurement of sodium polarizability by Ekstrom et al. [Phys. Rev. A 51, 3883 (1995)] to find ${\alpha }_{\mathrm{K}}=43.06(21)$ and ${\alpha }_{\mathrm{Rb}}=47.24(21)$. DOI: http://dx.doi.org/10.1103/PhysRevA.81.053607 © 2010 The American Physical Society