Suppression of systematic effects in a single-species atomic comagnetometer

The atomic comagnetometer is capable of reducing the effect of magnetic-field variations through comparing the synchronous measurement results from at least two magnetometers. A new configuration of comagnetometer is based on an ensemble of identical atoms or molecules, and possesses the ability to suppress the magnetic-field-gradient-induced systematic effect. We present a comprehensive analysis on the systematic effects of a single-species cesium atomic comagnetometer. Experimental results reveal that the dominant systematic effect arises from the light shift. We propose a method to suppress the light-shift-induced systematic effect, combined with quantitative investigations on other sources of systematic effects. The optimized system is able to search for the hypothetical spin-dependent gravitational energy of a proton at a level of ${10}^{\ensuremath{-}19}$ eV.