Magnetic quantization of electronic states in d-wave superconductors

We derive a general quasiclassical approach for long-range magnetic-field q uantization effects in superconductors. The method is applied to superclean d-wave superconductors in the mixed state for delocalized states with ener gies is an element of much greater than Delta(0)root H/H-c2. We find that t he energy spectrum consists of narrow energy bands whose centers are locate d at the Landau levels calculated in the absence of the vortex potential. W e show that transitions between the states belonging to the different Landa u levels can he observed experimentally due to resonances in the ac vortex friction.