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 ${\ensuremath{\alpha}}_{\mathrm{Na}}=24.11(2){}_{\mathrm{stat}}(18){}_{\mathrm{sys}}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}24}{\mathrm{cm}}^{3}$, ${\ensuremath{\alpha}}_{\mathrm{K}}=43.06(14)(33)$, and ${\ensuremath{\alpha}}_{\mathrm{Rb}}=47.24(12)(42)$. 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 ${\ensuremath{\alpha}}_{\mathrm{Rb}}/{\ensuremath{\alpha}}_{\mathrm{Na}}=1.959(5)$, ${\ensuremath{\alpha}}_{\mathrm{K}}/{\ensuremath{\alpha}}_{\mathrm{Na}}=1.786(6)$, and ${\ensuremath{\alpha}}_{\mathrm{Rb}}/{\ensuremath{\alpha}}_{\mathrm{K}}=1.097(5)$. 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 ${\ensuremath{\alpha}}_{\mathrm{K}}=43.06(21)$ and ${\ensuremath{\alpha}}_{\mathrm{Rb}}=47.24(21)$.