Decoupling measurement and closed-loop suppression of transverse magnetic field drift in a modulated double-cell atomic comagnetometer

The long-term stability of the atomic comagnetometer is significantly influenced by transverse magnetic field drift. We describe a modulated double-cell atomic comagnetometer for decoupling measurement and closed-loop suppression of transverse magnetic field drift. Inertial signals and magnetic field signals are measured simultaneously in this configuration. Combined with magnetic field modulation, a method to achieve decoupled measurement of transverse magnetic field is introduced. A closed-loop system for transverse magnetic field is constructed, and its effectiveness is verified experimentally. The results demonstrate that the transverse magnetic field is successfully decoupled and measured within the double-cell configuration. The sensitivity of magnetic field measurement is an order of magnitude higher than that of traditional single-cell comagnetometers. Moreover, the long-term stability of the atomic comagnetometer output signal in closed-loop mode is improved 31.0%. The proposed configuration and method effectively suppress magnetic field drift, which is of great importance for advancing atomic comagnetometer applications.