Simulation Analysis of Quantum Noise Impact on Cold Atom Interferometry Gravimeters

Cold Atom Interferometry Gravimeters (CAIGs) are at the forefront of high-precision gravity sensing. Understanding the fundamental noise sources that limit their performance is crucial for their continued development and application. This paper presents a comprehensive simulation model designed to systematically analyze the impact of intrinsic static noise sources, primarily Quantum Projection Noise (QPN) and laser phase noise, on CAIG performance. The model facilitates a quantitative investigation into how key operational parameters—such as atom number, interferometer contrast, free-evolution time, and laser noise spectral characteristics—affect the gravimeter’s sensitivity and stability, which are characterized using Allan deviation and the Power Spectral Density (PSD) of the measurement error. Simulation results quantify the QPN limit, scaling as N-1/2 (where N is atom number), which for 106 atoms corresponds to a short-term Allan deviation on the order of 5 × 10–10 m/s2/√Hz (value to be filled from simulation). Laser phase noise with a white noise floor above approximately 10–9 rad2/Hz begins to significantly degrade performance beyond the QPN limit for 106 atoms. Furthermore, residual vibration noise, even with idealized compensation assumptions in this static noise focused study, can manifest as distinct spectral peaks in the error PSD, underscoring its pervasive nature. This work provides a robust framework for dissecting noise contributions, identifying performance bottlenecks, and offers quantitative insights to guide the optimization of CAIGs towards their theoretical sensitivity limits in engineered systems.