Enhanced transverse nuclear magnetization of an atomic co-magnetometer at the optimal oscillating magnetic field

Abstract

The nuclear magnetization produced by hyperpolarized noble-gas molecules of co-magnetometers presents excellent potential in ultrahigh accuracy measurement. Here we demonstrate an optimization method of the oscillating magnetic field to enhance the transverse nuclear magnetization for atomic co-magnetometers operated in the nuclear magnetic resonance (NMR) regime. Under normal operating conditions, the absolute magnetic field produced by transverse nuclear magnetization is studied based on the nuclear spin dynamics and measured by the in-situ magnetometer experimentally. The different oscillating magnetic fields are applied to obtain the maximum transverse nuclear magnetization in various operating temperatures. Combined with the measurements, we reveal the relationship between the transverse nuclear magnetization and the relaxation time, which is consistent with our method. The optimization method makes selecting the optimal operating point for each atomic co-magnetometer quick and accurate to enhance transverse nuclear magnetization. In addition, operating at the optimal oscillating magnetic field can effectively reduce the bias instability of the atomic co-magnetometer.