Measurement of the ratio between g-factors of the ground states of ${}^{87}$Rb and ${}^{85}$Rb

Abstract

The ratio between the Landé g-factors of the ${}^{87}$Rb $F=2$ and ${}^{85}$Rb $F=3$ ground state hyperfine levels is experimentally measured to be $g_F(87)/g_F(85)=1.4988586(1)$, consistent with previous measurements. The g-factor ratio is determined by comparing the Larmor frequencies of overlapping ensembles of ${}^{87}$Rb and ${}^{85}$Rb atoms contained within an evacuated, antirelaxation-coated vapor cell. The atomic spins are polarized via synchronous optical pumping and the Larmor frequencies are measured by off-resonant probing using optical rotation of linearly polarized light. The accuracy of this measurement of $g_F(87)/g_F(85)$ exceeds that of previous measurements by a factor of $\approx 50$ and is sensitive to effects related to quantum electrodynamics.

8 pages, 6 figures, 1 table