Anomalous Orbital Magnetism and Hall Effect of Massless Fermions in Two Dimension

TL;DR

This paper theoretically investigates the inter-band effects of magnetic fields on orbital magnetic susceptibility and Hall effect in two-dimensional massless fermions, revealing singular behaviors near the zero-gap region.

Contribution

It introduces a theoretical analysis of magnetic responses in 2D massless fermions described by Weyl equations, including tilted Weyl models relevant to molecular solids.

Findings

Orbital susceptibility and Hall conductivity depend strongly on Fermi energy.

Both quantities exhibit singular behavior near the zero-gap region.

Dependences scale with elastic scattering time.

Abstract

Inter-band effects of magnetic field on orbital magnetic susceptibility and Hall effect in weak magnetic field have been studied theoretically at absolute zero for the model of massless Fermions in two dimension described by Weyl equation similar to graphenes, which are simplified version of newly found one in molecular solids, arfa-ET2I3 described by "tilted Weyl" equation. The dependences on the Fermi energy of both orbital susceptibility and Hall conductivity near the zero-gap region scale with elastic scattering time and then are very singular.