Orbital diamagnetism in multilayer graphenes: Systematic study with the effective mass approximation

TL;DR

This paper provides a theoretical analysis of orbital diamagnetism in multilayer graphene, revealing how susceptibility contributions depend on layer number and subband types, with distinctive features at the Fermi energy.

Contribution

It systematically decomposes the susceptibility into monolayer- and bilayer-like contributions within the effective mass approximation, highlighting their unique behaviors.

Findings

Monolayer-type subband shows delta-function susceptibility at zero Fermi energy.

Bilayer-type subband exhibits singular and logarithmic susceptibility features.

Total susceptibility scales approximately with the number of layers.

Abstract

We present a theoretical study on the orbital magnetism in multilayer graphenes within the effective mass approximation. The Hamiltonian and thus susceptibility can be decomposed into contributions from sub-systems equivalent to monolayer or bilayer graphene. The monolayer-type subband exists only in odd layers and exhibits a delta-function susceptibility at $E_F=0$. The bilayer-type subband appearing in every layer number gives a singular structure in the vicinity of $E_F=0$ due to the trigonal warping as well as a logarithmic tail away from $E_F=0$. The integral of the susceptibility over energy is approximately given only by the layer number.