Chiral orbital current and anomalous magnetic moment in gapped graphene

Mikito Koshino

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)

Abstract

We present a low-energy effective-mass theory to describe a chiral orbital current and an anomalous magnetic moment in graphenes with a band gap and related materials. We explicitly derive a quantum-mechanical current distribution in general Bloch electron systems, which describes a chiral current circulation supporting the magnetic moment. We apply the formulation to gapped graphene monolayer, bilayer, and ABC-stacked multilayers to show that the chiral current is opposite between different valleys, and the corresponding magnetic moment accounts for valley splitting of Landau levels. In a gapped bilayer and ABC multilayer graphenes, in particular, the valley-dependent magnetic moment is responsible for huge paramagnetic susceptibility at low energy, which enables a full valley polarization up to relatively high electron densities. The formulation also applies to the gapped surface states of a three-dimensional topological insulator, where the anomalous current is related to the magnetoelectric response in a spatially modulated potential.

Original languageEnglish
Article number125427
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume84
Issue number12
DOIs
Publication statusPublished - 2011 Sep 12

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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