Partial measurements of the total field gradient and the field gradient tensor using an atomic magnetic gradiometer

Magnetic gradiometers have wide practical and academic applications, and two important types of field gradient observables are the total field gradient and field gradient tensor. However, measurements of the field gradient tensor have not been the focus of previous researches on atomic magnetic gradiometers. In this work, we develop an atomic magnetic gradiometer based on two separately optically pumped atomic ensembles in a Herriott-cavity-assisted atomic cell. This gradiometer shows versatile operation modes and functions, and we demonstrate them in measurements of both types of field gradient observables.