de Haas-van Alphen effect in a two-dimensional metal with Fermi energy near the van Hove singularity

The nature of magneto-quantum oscillations in quasi-two-dimensional metals with Fermi energy near van Hove singularity (vHs) is investigated. Around the vHs the electron spectrum consists of significantly broadened spin-split Landau levels (Landau bands). One of the spin-split subbands shows magnetic-field-dependent cyclotron mass, increasing strongly around the magnetic field where the quasi Fermi level crosses the vHs energy, and manifesting in a peculiarly suppressed magnetization oscillation pattern. Above this field the oscillation amplitudes exhibit modulatory behavior due to the effect of magnetic breakdown.