Broken sublattice symmetry states in Bernal stacked multilayer graphene

TL;DR

This paper investigates the ordered electronic phases in Bernal stacked multilayer graphene, focusing on interaction-induced band gaps and sublattice symmetry breaking, revealing complex phase diagrams influenced by external electric fields.

Contribution

It introduces a detailed analysis of sublattice symmetry breaking and pseudospin doublets in multilayer graphene, highlighting new phase behaviors under external electric fields.

Findings

Identification of light-mass and heavy-mass pseudospin doublets with opposite charge polarization

Discovery of an effective Hund's rule governing pseudospin ordering in tetralayer graphene

Complex phase diagrams emerging with increasing layer number under external electric fields

Abstract

We analyze the ordered phases of Bernal stacked multilayer graphene in the presence of interaction induced band gaps due to sublattice symmetry breaking potentials, whose solutions can be analyzed in terms of light-mass and heavy-mass pseudospin doublets which have the same Chern numbers but opposite charge polarization directions. The application of a perpendicular external electric field reveals an effective Hund's rule for the ordering of the sublattice pseudospin doublets in a tetralayer, while a similar but more complex phase diagram develops with increasing layer number.