Magnetometer based on atomic coherence and possible application to the search for P and T violating permanent electric dipole moments of atoms

A new approach to the experimental search for P and T violating permanent electric dipole moments (EDMs) in atoms is proposed. The high dispersion of a phase coherent atomic medium at a point of electromagnetically induced transparency is used to detect linear Stark-shifts associated with an atomic EDM in a highly sensitive interferometric measurement. Possible noise sources are analysed and estimates are given for the device sensitivity.