Numerical study on electron-electron interaction and ferromagnetic fluctuation in graphene

ORAL

Abstract

Within the Hubbard model on a honeycomb lattice, we investigate the effect of electron-electron interactions and ferromagnetic fluctuations in graphene numerically. We find that the system in the filling region $<$$n$$>$=1.60-1.90 shows a short-ranged ferromagnetic correlation, and the on-site Coulomb interaction tends to strengthen ferromagnetic fluctuation slightly. Furthermore, the ferromagnetic fluctuation is strengthened markedly as the next-nearest neighbor hoping energy increases, which indicate that the next-nearest neighbor hoping term plays an important role in graphene since it breaks the particle-hole symmetry.

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Authors

  • Tian-Xing Ma

    • Max Planck Institute for the Physics of Complex Systems, Noethnitzer Str. 38, D-01187 Dresden, Germany
    • Department of Physics and the Institute of Theoretical Physics, the Chinese University of Hong Kong

  • Feiming Hu

    • Department of Physics and the Institute of Theoretical Physics, the Chinese University of Hong Kong

  • Zhongbing Huang

    • Faculty of Physics and Electronic Technology, Hubei University, Wuhan 430062, People&#039;s Republic of China

  • Hai-Qing Lin

    • The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
    • The Chinese University of Hong Kong, Shatin, Hong Kong
    • Department of Physics and the Institute of Theoretical Physics, the Chinese University of Hong Kong
    • Department of Physics, The Chinese University of Hong Kong