Disappearance of the Dirac cone in silicene due to the presence of an electric field
D. A. Rowlands, Zhang Yu-Zhong (张宇钟)
Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
Abstract 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 the 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.
(Metal-insulator transitions and other electronic transitions)
Fund: 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, and the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the Education Ministry of China.
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