Influence of antiferromagnetic ordering on the de Haas-van Alphen effect in a semimetal

The distinctive characteristics of the de Haas-van Alphen effect in semimetals with antiferromagnetic long-range order are investigated theoretically. It is shown that the transition of the subsystem of localized spins from the canted antiferromagnetic phase to the ferromagnetic phase is accompanied by an abrupt change in the ''frequency'' of the magnetization oscillations of band carriers M-similar to. In the below-critical range of magnetic fields, M-similar to is not a function periodic in 1/H. Significantly, the additional contribution to the phase of the oscillatory factors is proportional to H-2 and is determined entirely by quantum fluctuations in the antiferromagnetic subsystem. (C) 1997 American Institute of Physics.