Ghost excitonic insulator transition in layered graphite

TL;DR

This paper proposes that layered graphite exhibits properties due to its proximity to an excitonic insulator phase, which can be stabilized in doped, stacked graphene layers, explaining unusual electronic behaviors.

Contribution

It introduces the concept of a ghost excitonic insulator transition in layered graphite, linking its properties to a nearby excitonic phase stabilized by stacking and doping.

Findings

Layered graphite's properties are explained by proximity to an excitonic insulator phase.

Doped stacked graphene layers can stabilize the excitonic insulator phase.

Unusual electronic behaviors in graphite are linked to this transition.

Abstract

Some unusual properties of layered graphite, including a linear energy dependence of the quasiparticle damping and weak ferromagnetism at low doping, are explained as a result of the proximity of a single graphene sheet to the excitonic insulator phase which can be further stabilized in a doped system of many layers stacked in the staggered ($ABAB...$) configuration.