Angle Dependence of Magnetic Oscillations in (TMTSF)2FSO3

The angle dependence of the Shubnikov-de Haas (SdH) oscillations was studied to obtain a complete picture of the Fermi surface for (TMTSF) 2 FSO 3 showing unexpectedly the Yamaji angular oscillations instead of the Lebed's ones. The SdH frequency follows the perfect two-dimensional (2D) behavior; F=F 0 /cosθ, where the minimum frequency F 0 = (130±0.5) T corresponds to 1.6% of the first Brillouin zone. The angle dependence of the SdH amplitude revealing drastic and unexpected effects will be discussed with spin splitting and topological points of view.