Transverse magnetization and Hertzian

Transverse magnetization and Hertzian ooherenee in optical pumping experiments 

However, recalling the extensive discussion of the density matrix in section 15.5.5, we recognize that it may be possible in certain optical pumping experiments to prepare atoms in such a way that the relative phases of the probability amplitudes a (t) and a (t) of the states y and y do not vary randomly from one atom to another. The ground-state density matrix then has finite off-diagonal elements. We recall that these off-diagonal elements evolve in time according to 

In this experiment the magnetic dipole moment of an atom which has just completed the optical pumping cycle at time tQ finds itself pointing along the Ox axis. Immediately afterwards it starts to precess about the magnetic field B at the Larmor angular frequency oj of the ground-state atoms. This precession does not last indefinitely for after a mean time x the orientation of the atom is destroyed by a collision or by absorption of another photon. In order to 

The components of the transverse magnetization can be obtained as functions of the applied field by using the tech- 

These predictions have been confirmed experimentally by Lehmann and Cohen-Tannoudji (1964) using Cd (1=1/2) pumped by the 5 - 5 transition at 2288 S. The ex- 

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