Magnetic field screening and mirroring in graphene

TL;DR

This paper investigates how monolayer graphene uniquely screens and mirrors magnetic fields, acting as a magnetic shield with a strong diamagnetic response at low Fermi wave numbers, unlike conventional 2D systems.

Contribution

It reveals that graphene can serve as an effective magnetic shield and mirror, with a significantly enhanced diamagnetic force at small Fermi wave numbers, expanding understanding of orbital magnetism in 2D materials.

Findings

Graphene screens magnetic fields more effectively than conventional 2D systems.

Graphene acts as a magnetic mirror with a diamagnetic force.

The shielding effect diminishes as the Fermi wave number increases.

Abstract

The orbital magnetism in spatially varying magnetic fields is studied in monolayer graphene within the effective mass approximation. We find that, unlike the conventional two-dimensional electron system, graphene with small Fermi wave number k_F works as a magnetic shield where the field produced by a magnetic object placed above graphene is always screened by a constant factor on the other side of graphene. The object is repelled by a diamagnetic force from the graphene, as if there exists its mirror image with a reduced amplitude on the other side of graphene. The magnitude of the force is much greater than that of conventional two-dimensional system. The effect disappears with the increase of k_F.