Origin Of Magnetism in Graphene Nanostructures

POSTER

Abstract

The magnetic orderings of traditional magnetic materials originate from their partially filled $d$- or $f$-electron bands. Surprisingly, theoretical and experimental studies show that graphene nanostructures which contain only $s$ and $p$ electrons can also exhibit magnetic ground states. On the basis of the bonding properties of $pi$-electrons, we propose a theoretical model to explain the origin of magnetism in graphene nanostructures. Our theory is justified via examples ranging from nanoflakes to nanoribbons. Our theory also provides a simple physical insight into Lieb's theorem about the ground state magnetic momentum of a bipartite system.

Authors

  • Wen Ying Ruan

    School of Physics, Georgia Institute of Technology, Atlanta 30332, USA

  • Yiyang Sun

    Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA

  • Shengbai Zhang

    Rensselaer Polytechnic Institute, Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA

  • Mei-Yin Chou

    Insitute of Atomic and Molecular Science, Academia Sinica, Taipei, Taiwan and Georgia Institute of Technology, Atlanta, Georgia, USA, School of Physics, Georgia Institute of Technology, Atlanta 30332, USA, and IAMS, Academia Sinica, Taipei, Taiwan, School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipe