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

TL;DR

This paper studies giant quantum oscillations in the longitudinal magnetoresistance of quasi-two-dimensional metals, revealing conditions for large oscillations and their thermal activation behavior in high magnetic fields.

Contribution

It provides a theoretical analysis of quantum oscillations in magnetoresistance, highlighting the giant oscillations in the two-dimensional limit and their thermal activation in specific materials.

Findings

Giant Shubnikov-de Haas oscillations occur when the cyclotron energy exceeds interlayer transfer integral.

Magnetoconductivity minima show thermally activated behavior at high fields and low temperatures.

Absence of strong chemical potential oscillations in organic layered conductors is discussed.

Abstract

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 $\hbar \omega_{c}$ 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 $\beta''\mathrm{-(BEDT-TTF)}_{2}\mathrm{SF}_{5}\mathrm{CH}_{2}\mathrm{CF}_{2}\m athrm{SO}_{3}$. The questions concerning the absence of strong chemical potential oscillations in such compound and the impurity self-energy are discussed.