Theoretical Proposal of a Digital Closed-Loop Thermal Atomic-Beam Interferometer for High-Bandwidth, Wide-Dynamic-Range, and Simultaneous Absolute Acceleration-Rotation Sensing

Abstract: We present a theoretical proposal and simulation study of a digital closed-loop thermal atomic-beam interferometer offering high bandwidth, wide dynamic range, and simultaneous absolute acceleration and rotation sensing, suitable for inertial navigation applications. The scheme synchronizes phase biasing with momentum-kick reversal through the atomic transit time of the interferometer, extracting four interferometric phases to suppress Raman beam path-length errors, while two-photon detuning feedback maintains a pseudo-inertial frame and eliminates cross-coupling. In simulations with a $170^{\circ} {\rm C}$ $^{85}$Rb beam and an interferometer arm length of 100~mm, the approach achieves sensitivities of $3{\rm \mu m / s^2 / \sqrt{Hz}}$ (velocity random walk) and $15{\rm \mu deg / \sqrt{h}}$ (angular random walk), surpassing state-of-the-art inertial sensors.