Real-time high-sensitivity magnetic and inertial sensing based on nuclear spin pulse modulation in atomic comagnetometers

Ultrahigh-sensitivity quantum magnetic field sensing and inertial rotation sensing have key applications in fundamental physics, medical imaging, and novel inertial navigation. However, the performance of atomic inertial sensing is constrained by magnetic field-induced errors that are difficult to decouple. To address the problem of magnetic-inertial coupling in the comagnetometers, this paper innovatively proposes a real-time, high-sensitivity measurement scheme for both magnetic field (B) and rotation (Ω) based on nuclear spin pulse modulation. The scheme actively manipulates the quantum states of nuclear spins through pulse modulation. By leveraging the switching of nuclear spin states, the magnetic field information sensed by electron spins is expanded. This approach addresses the inherent underdetermination problem in conventional comagnetometers, where two output signals are insufficient to uniquely solve for four unknown input parameters (B_x/y, Ω_x/y). By transforming the system into a fully determined one, it lays the physical groundwork for the decoupling of B and Ω. Furthermore, the measurement model is constructed based on the characteristic information extracted from electron spin evolution. While the full-dimensional validation is currently constrained by experimental hardware, the proposed scheme is experimentally verified through the simultaneous measurement of three parameters (B_x, B_y, and Ω_y) via Kalman filtering. The experimental results demonstrate successful decoupling with magnetic field measurement sensitivities of 0.71 pT/Hz (B_x) and 0.30 pT/Hz (B_y), and an inertial measurement sensitivity of 2.53×10^{−5 ∘}/s/Hz (Ω_y).