Exceptional points in an optically pumped magnetometer

The exceptional points (EPs) in a system are the eigenvalue degeneracy that has been demonstrated in a wide range of optical arrangements. In this paper, EP is analyzed schematically in an optically pumped magnetometer, which is governed by the Bloch equation with a 3×3 matrix. We numerically illustrate EP enhanced sensing for magnetic field and EP encircling induced 2π phase shift by employing the sensing field along with transverse modulation field. These findings may contribute to the realization of EP magnetometers and atomic gyroscopes for improved field and rotation sensitivity.