Energy in a magnetic field

Fig. 21. Faraday rotation for a 2- m thick film of Ga Mn.rAs with x = 0.043 measured as a function of the photon energy in a magnetic field of 6 T at 10 and 300 K (a) and as a function of the magnetic field at 10 K, 1.55 eV and at 300 K, 1.49 eV (b). Solid lines show the magnetization determined from magnetotransport measurements at the given temperatures (scaled to match the open symbols) (Kuroiwa et al. 1998).

Let us now take an S manifold, unsplit at zero magnetic field, with no orbital angular momentum. The sum of the energies in a magnetic field would be zero... 

More specifically, the total energy in a magnetic field can be written, to first order, as a sum of three contributions ... 

The absorption of energy stimulating transitions between the two levels of energy in a magnetic field is called magnetic resonance. Thus, the resonance condition obtained by equaling Eo to AE can be expressed either as ... 

Confining our attention to the first and second doublet, the energies in a magnetic field are obtained from Eqs. (85 and 89) to first order in... 

In the same way as a magnetic dipole acquires an orientational energy in a magnetic field, a non-spherically symmetric charge distribution will acquire such an energy in an electric field gradient (Fig.2.17). 

Different spin states have different energies in a magnetic field. 

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