Linear magnetoresistance of two-dimensional massless Dirac fermions in the quantum limit

TL;DR

This paper provides a theoretical analysis of linear magnetoresistance in 2D massless Dirac fermions, explaining experimental observations and revealing a linear resistivity dependence on magnetic field in the quantum limit.

Contribution

It derives analytical expressions for magnetoresistivity of 2D Dirac fermions, explaining experimental linear magnetoresistance and minimum conductivity in the quantum limit.

Findings

Resistivity depends linearly on magnetic field for Gaussian impurities.

Recovers the minimum conductivity in the clean limit.

Quantitative agreement with experimental data.

Abstract

Linear magnetoresistance is a hallmark of 3D Weyl metals in the quantum limit. Recently, a pronounced linear magnetoresistance has also been observed in 2D graphene [Xin et al., Nature 616, 270 (2023)]. However, a comprehensive theoretical understanding remains elusive. By employing the self-consistent Born approximation, we derive the analytical expressions for the magnetoresistivity of 2D massless Dirac fermions in the quantum limit. Notably, our result recovers the minimum conductivity in the clean limit and reveals a linear dependence of resistivity on the magnetic field for Gaussian impurity potentials, in quantitative agreement with experiments. These findings shed light on the magnetoresistance behavior of 2D Dirac fermions under ultra-high magnetic fields.