SUPERCONDUCTORS IN STRONG MAGNETIC-FIELDS - DEHAAS-VANALPHEN EFFECT

We consider superconductors in strong magnetic fields in the mixed state when the orbital quantization of the electrons is important. By averaging over the Abrikosov vortex lattice, solutions are obtained for the Green's function and gap parameter in the quantum case. These solutions are appropriate to describe phenomena on a scale large compared with the vortex-line separation and are independent of the detailed vortex configuration. These results are used to calculate the de Haas-van Alphen oscillations in the free energy in the mixed state. The effects of spin splitting and a layered structure are discussed.