Realistic hofstadter energy spectrum and ensemble dependent de haas-van alphen effect in α-(ET)2KHg(SCN)4

We investigate the magnetic breakdown effect(MB) in a quasi 2 dimensional organic conductor, α-(ET)2KHg(SCN)4 with a full quantum mechanical tight binding model. The realistic Hofstadter type energy spectrum vs magnetic field is obtained and thermodynamic quantities are calculated using energy eigenvalues. Our ensemble dependent de Haas van Alphen (dHvA) results indicate combination frequencies, especially β-α and β+a orbits, in both canonical and grand canonical ensembles.