Postselected amplification applied to atomic magnetometers

We propose to embed the atomic magnetometer (AM) into an optical Mach-Zehnder interferometer (MZI). We analyze the effect of amplification of the Faraday rotation angle of the probe laser light, by properly postselecting the path-information state of the laser photons when passing through the MZI. The proposed scheme provides a postselected metrological protocol of probing weak magnetic fields, having a potential to further enhance the sensitivity of the nowadays state-of-the-art optical AM.