Giant quantum oscillations of the longitudinal magnetoresistance in quasi-two-dimensional metals

Abstract

We have investigated in frame of the quantum transport theory the magnetic quantum oscillations of the longitudinal magnetoresistance ρ zz in quasi-two-dimensional (2D) metals for a magnetic field perpendicular to the layers. Giant Shubnikov–de Haas oscillations are found when the cyclotron energy ℏ ω c is much larger than the interlayer transfer integral t (the 2D limit). In large magnetic fields and at low temperatures, the minima of the magnetoconductivity σ zz = ρ zz −1 exhibit a thermally activated behavior in presence of negligibly small chemical potential oscillations, as observed in the organic layered conductor β″−(BEDT−TTF) 2SF 5CH 2CF 2SO 3. The questions concerning the absence of strong chemical potential oscillations in such compound and the impurity self-energy are discussed.