Chiral Decomposition in the Electronic Structure of Graphene Multilayers

TL;DR

This paper reveals that multilayer graphene's low-energy electronic structure comprises chiral pseudospin doublets, with the total pseudospin chirality always summing to the number of layers, affecting Landau levels and Hall conductivity.

Contribution

It introduces a framework describing the electronic structure of arbitrarily stacked graphene multilayers using chiral pseudospin doublets, regardless of stacking sequence.

Findings

Number of Landau levels at E=0 equals the number of layers.

Quantized Hall conductivity depends on the number of layers and an integer n.

Pseudospin chirality sum always equals the number of layers.

Abstract

We show that the low-energy electronic structure of arbitrarily stacked graphene multilayers with nearest-neighbor interlayer tunneling consists of chiral pseudospin doublets. Although the number of doublets in an $N$-layer system depends on the stacking sequence, the pseudospin chirality sum is always $N$. $N$-layer stacks have $N$ distinct Landau levels at E=0 for each spin and valley, and quantized Hall conductivity $\sigma_{xy} = \pm(4 e^2/h)(N/2+n)$ where $n$ is a non-negative integer.