Magnetic noise suppression based on mid-frequency magnetic field response in SERF atomic comagnetometers

The atomic comagnetometers (ACMs) based on the spin-exchange relaxation-free (SERF) regime exhibit extremely high sensitivity in angular velocity measurements, positioning them as leading candidates for next-generation precision inertial sensing. However, magnetic noise remains a significant factor that contributes significantly to long-term bias drift. Here, a comprehensive model in full-frequency band of the angular velocity measurement error induced by magnetic noise in ACMs is established. Based on the proposed model, what we believe to be a new method is proposed to reduce magnetic noise error by suppressing the magnetic field response in the mid-frequency range. After optimizing the temperature of the vapor cell to minimize the magnetic field response in the mid-frequency range, the angular velocity measurement error caused by magnetic noise was reduced by 20.4%, and the bias drift was improved by 34.8%. The theories and methods proposed in this study innovatively highlight the critical role of mid-frequency magnetic field responses in suppressing magnetic noise errors, and provide important guidance for improving bias drift in SERF ACMs.