摘要
Using the two-dimensional ionic Hubbard model as a simple basis for describing the electronic structure of silicene in the presence of an electric field induced by the substrate, we use the coherent-potential approximation to calculate tbe zero-temperature phase diagram and the associated spectral function at half filling. We find that any degree of symmetry- breaking induced by the electric field causes the silicene structure to lose its Dirac fermion characteristics, thus providing a simple mechanism for the disappearance of the Dirac cone.
Using the two-dimensional ionic Hubbard model as a simple basis for describing the electronic structure of silicene in the presence of an electric field induced by the substrate, we use the coherent-potential approximation to calculate tbe zero-temperature phase diagram and the associated spectral function at half filling. We find that any degree of symmetry- breaking induced by the electric field causes the silicene structure to lose its Dirac fermion characteristics, thus providing a simple mechanism for the disappearance of the Dirac cone.
基金
Project supported by the National Natural Science Foundation of China (Grant No. 11174219)
the Program for New Century Excellent Talents in Universities,China (Grant No. NCET-13-0428)
the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20110072110044)
the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, China
the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the Education Ministry of China
