Quantization of coupled orbits in metals

Abstract The failure of semi-elassical quantization of electron orbits in metals in the presence of a strong enough magnetic field (magnetic breakthrough) is discussed in an elementary fashion by means of first-order perturbation theory. The interference effects, which arise when orbits about different centres are coupled, are reproduced in a simple network analogue. Exact analysis of the network shows how the energy levels are broadened by the coupling and eventually reform into a different set of levels. Fourier analysis of the level density reveals what might be observed in the de Haas—van Alphen effect when magnetic breakthrough is significant, and it is concluded that in principle the whole evolution of the level system should be observable.