Ag(111)-$\surd $3$\times$$\surd $3-Silicene Versus Si(111)-$\surd $3$\times$$\surd $3-Ag surface
ORAL
Abstract
Since 2012, silicene has been successfully grown on Ag(111) surface. We have provided reasonable atomic models of $\surd $3$\times$$\surd $3 silicene. However, the atomic and electronic structures of $\surd $3$\times$$\surd $3 silicene are still heavily debating, especially, it is easily to be confused to the Si(111)-$\surd $3$\times$$\surd $3-Ag surface. Here, I give a report of our recent works on silicene. With first-principles calculations combined with STM observations, we studied the structures of multilayer silicene on Ag(111) substrates, which all have $\surd $3$\times$$\surd $3 relaxed surfaces, and diamond-like stacking mode. Both calculations and STS show such silicon surface has strong Dirac-cone-like surface state, indicating the multilayer silicene possesses a new kind of silicon surface. The Si(111)-$\surd $3$\times$$\surd $3Ag surface is further compared to epitaxial silicene. It is found that the simulated STM images of both surfaces are similar, the there is also strong surface state for Si(111)-$\surd $3$\times$$\surd $3-Ag surface. However, the different temperatures for symmetry-breaking phase transitions and different H-adsorption structures can be used for distinguishing such two surfaces.
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Authors
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Hui Li
State Key Laboratory for Surface Physics, Institute of Physics Chinese Academy of Sciences