Demonstration of magnetically silent optically pumped magnetometers for the TUCAN electric dipole moment experiment.

We report the performance of a magnetically silent optically pumped cesium magnetometer with a statistical sensitivity of 3.5 pT/ at 1 Hz and a stability of 90 fT over 150 s of measurement. Optical pumping with coherent, linearly-polarized, resonant light leads to a relatively long-lived polarized ground state of the cesium vapour contained in a measurement cell.