Orbital magnetism of graphene flakes

Yuya Ominato, Mikito Koshino

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)

Abstract

Orbital magnetism is studied for graphene flakes with various shapes and edge configurations using the tight-binding approximation. In the low-temperature regime where the thermal energy is much smaller than the energy-level spacing, the susceptibility rapidly changes between diamagnetism and paramagnetism as a function of Fermi energy, in accordance with the energy-level structure. The susceptibility at the charge neutral point is generally larger in armchair flake than in zigzag flake, and larger in hexagonal flake than in triangular flake. As the temperature increases, the discrete structures due to the quantum confinement are all gone, and the susceptibility approximates the bulk limit independently of the atomic configuration. The diamagnetic current circulates entirely on the graphene flake at zero temperature, while in increasing temperature it is localized near the edge with the characteristic depth proportional to 1/T. We predict that the diamagnetism of graphene can be observed using the alignment of graphene flakes in a feasible range of magnetic field.

Original languageEnglish
Article number115433
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume87
Issue number11
DOIs
Publication statusPublished - 2013 Mar 25

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Orbital magnetism of graphene flakes'. Together they form a unique fingerprint.

Cite this