Scaling properties of induced density of chiral and non-chiral Dirac fermions in magnetic fields

TL;DR

This paper investigates how repulsive potentials influence the induced density and scaling properties of Landau levels in both chiral and non-chiral Dirac fermions in graphene under magnetic fields, revealing regime-dependent behaviors.

Contribution

It provides a detailed analysis of the scaling properties and induced densities of Dirac fermions in magnetic fields, highlighting differences between chiral and non-chiral cases across coupling regimes.

Findings

In strong coupling, the density inside the potential exceeds the free value.

In weak coupling, the induced density becomes negative.

Different power-law behaviors are observed for chiral and non-chiral fermions.

Abstract

We find that a repulsive potential of graphene in the presence of a magnetic field has bound states that are peaked inside the barrier with tails extending over \ell(N + 1), where \ell and N are the magnetic length and Landau level(LL) index. We have investigated how these bound states affect scaling properties of the induced density of filled Landau levels of massless Dirac fermions. For chiral fermions we find, in strong coupling regime, that the density inside the repulsive potential can be greater than the value in the absence of the potential while in the weak coupling regime we find negative induced density. Similar results hold also for non-chiral fermions. As one moves from weak to strong coupling regimes the effective coupling constant between the potential and electrons becomes more repulsive, and then it changes sign and becomes attractive. Different power-laws of induced density are found for chiral and non-chiral fermions.