Precision measurement of magnetic field based on the transient process in a K-Rb-²¹Ne co-magnetometer.

We demonstrate a novel method of measuring magnetic field based on the transient signal of the K-Rb-²¹Ne co-magnetometer operating in nuclear spin magnetization self-compensation magnetic field regime. The operation condition for self-compensation magnetic field by nuclear spin magnetization of ²¹Ne in steady state is presented. We characterize the dynamics of the coupled spin ensembles by a set of Bloch equations, and formulate the expression of transient output signal. After verifying the stability of this method, the measurement range and error are studied. This method is also verified to be valid in various temperature and pumping light power density.