Giant Quantum Oscillations of the Longitudinal Magnetoresistance in Quasi two-dimensional Metals

We have investigated in frame of the quantum transport theory the magnetic quantum oscillations of the longitudinal magnetoresistance ${\rho }_{zz}$ in quasi two-dimensional metals for a magnetic field perpendicular to the layers. Giant Shubnikov-de Haas oscillations are found when the cyclotron energy $\mathrm{\hslash }{\omega }_c$ is much larger than the interlayer transfer integral $t$ (the two-dimensional limit). In large magnetic fields and at low temperatures, the minima of the magnetoconductivity ${\sigma }_{zz}={\rho }_{zz}^{-1}$ exhibit a thermally activated behavior in presence of negligibly small chemical potential oscillations, as observed in the organic layered conductor $\beta’'$-(\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}-\mathrm{T}\mathrm{T}\mathrm{F})${2}$\mathrm{S}\mathrm{F}${5}$\mathrm{C}\mathrm{H}${2}$\mathrm{C}\mathrm{F}${2}\m athrm{SO}_{3}$. The questions concerning the absence of strong chemical potential oscillations in such compound and the impurity self-energy are discussed.