He3−Xe129 Comagnetometery using Rb87 Detection and Decoupling

Abstract

We describe a ${}^3\mathrm{He}\text{−}{}^{129}\mathrm{Xe}$ comagnetometer using ${}^{87}\mathrm{Rb}$ atoms for noble-gas spin polarization and detection. We use a train of ${}^{87}\mathrm{Rb}$ $\pi$ pulses and ${\sigma }^{+}/{\sigma }^{-}$ optical pumping to realize a finite-field Rb magnetometer with suppression of spin-exchange relaxation. We suppress frequency shifts from polarized Rb by measuring the ${}^3\mathrm{He}$ and ${}^{129}\mathrm{Xe}$ spin precession frequencies in the dark, while applying $\pi$ pulses along two directions to depolarize Rb atoms. The plane of the $\pi$ pulses is rotated to suppress the Bloch-Siegert shifts for the nuclear spins. We measure the ratio of ${}^3\mathrm{He}$ to ${}^{129}\mathrm{Xe}$ spin precession frequencies with sufficient absolute accuracy to resolve Earth’s rotation without changing the orientation of the comagnetometer. A frequency resolution of 7 nHz is achieved after integration for 8 h without evidence of significant drift.