Stable vector magnetometers based on electromagnetically induced transparency (EIT)

Magnetic sensors are widely used in many applications including medical diagnostics, geomagnetic survey, etc. Scalar atomic magnetometers that have demonstrated sensitivity at and below fT/ Hz^1/2 level can be adapted to include measurement of magnetic field orientation but usually at the cost of accuracy and with limitation of dynamic range. Magnetometry using electromagnetically induced transparency (EIT) instead was used to provide both scalar accuracy and vector information with angle resolution at a level of 10-3 deg/Hz^1/2. We present a scheme for EIT vector magnetic field measurement with the common-mode drift suppression by probing multiple EIT resonances. The demonstrated sensitivity is stable to < 200 pT/ Hz^1/2 at 1 mHz.