Magneto-quantum oscillations in kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br

ne Haas-van Alphen and Shubnikov-de Haas oscillations have been studied in the quasi-two-dimensional organic superconductor kappa-(BEDT-TTF)(2)Cu[N(CN )(2)]Br at different magnetic field orientations with respect to the conduc ting layers. At ambient pressure, the oscillation frequency spectrum reflec ts the Fermi surface topology predicted by band structure calculations. Est imates of the spin g-factors indicate discrepancies either in the g values or in the conformity to the Lifshitz-Kosevich formalism of charge carriers on different parts of the Fermi surface. In contrast to the standard theory , simultaneous de Haas-van Alphen and Shubnikov-de Haas experiments reveal a heating behavior of the magnetic breakdown oscillations in the de Haas-va n Alphen but not in the Shubnikov-de Haas signal within the studied field r ange.