Electronic transport in graphene with particle-hole-asymmetric disorder

TL;DR

This paper investigates how particle-hole asymmetry in disorder affects the electrical conductivity of graphene, revealing shifts in the minimal conductivity point depending on disorder strength through theoretical and numerical methods.

Contribution

It introduces a combined perturbative and numerical analysis of particle-hole asymmetric disorder effects on graphene's conductivity, highlighting the shift of the minimal conductivity away from the Dirac point.

Findings

Conductivity minimum shifts away from Dirac point due to asymmetry.

Weak disorder causes opposite shift directions compared to strong disorder.

At high disorder, the minimum aligns with equal electron and hole puddles.

Abstract

We study the conductivity of graphene with a smooth but particle-hole-asymmetric disorder potential. Using perturbation theory for the weak-disorder regime and numerical calculations we investigate how the particle-hole asymmetry shifts the position of the minimal conductivity away from the Dirac point $\varepsilon = 0$. We find that the conductivity minimum is shifted in opposite directions for weak and strong disorder. For large disorder strengths the conductivity minimum appears close to the doping level for which electron and hole doped regions ("puddles") are equal in size.