Influence of disorder on the magnetism of graphene bilayers
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, 210093, Nanjing, P.R. China
Corresponding author: a email@example.com
Revised: 6 June 2009
Published online: 15 July 2009
We numerically calculate the impact of site-energy disorder on the magnetism of biased bilayer graphene formed with the Bernal stacking. By using the mean-field method, we approximately solve the Hubbard Hamiltonian and calculate the average magnetization of the two layers, which indicates that the disorder does not change the nature of the first-order phase transition between paramagnetism and ferromagnetism, but may increase the critical interaction strength Uc of the Hubbard Hamiltonian for the system to become the ferromagnetic phase. We also calculate the dependencies of relevant physical quantities on temperature. The implications of the results are discussed.
PACS: 73.22.-f – Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals / 73.23.-b – Electronic transport in mesoscopic systems / 75.30.-m – Intrinsic properties of magnetically ordered materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009