Development of co-located ${}^{129}$Xe and ${}^{131}$Xe nuclear spin masers with external feedback scheme

TL;DR

This paper demonstrates co-located ${}^{129}$Xe and ${}^{131}$Xe nuclear spin masers with external feedback, significantly reducing frequency instability and achieving high precision, advancing potential applications in precision measurements.

Contribution

The study introduces a novel external feedback scheme for co-located ${}^{129}$Xe and ${}^{131}$Xe masers, enhancing stability and precision in spin precession measurements.

Findings

Frequency instability reduced by two orders of magnitude.

Achieved frequency precision of 6.2 μHz over 10,000 seconds.

Potential to reach 1 nHz precision with improved SNR.

Abstract

We report on the operation of co-located ${}^{129}$Xe and ${}^{131}$Xe nuclear spin masers with an external feedback scheme, and discuss the use of ${}^{131}$Xe as a comagnetometer in measurements of the ${}^{129}$Xe spin precession frequency. By applying a correction based on the observed change in the ${}^{131}$Xe frequency, the frequency instability due to magnetic field and cell temperature drifts are eliminated by two orders of magnitude. The frequency precision of 6.2 $\mu$Hz is obtained for a 10$^4$ s averaging time, suggesting the possibility of future improvement to $\approx$ 1 nHz by improving the signal-to-noise ratio of the observation.