Silicene, a sheet of silicon atoms in a honeycomb lattice, was proposed to be a new Dirac-type electron system similar as graphene. We performed scanning tunneling microscopy and spectroscopy studies on the atomic and electronic properties of silicene on Ag(111). An unexpected 3×3 reconstruction was found, which is explained by an extra-buckling model. Pronounced quasi-particle interferences (QPI) patterns, originating from both the intervalley and intravalley scattering, were observed. From the QPI patterns we derived a linear energy-momentum dispersion and a large Fermi velocity, which prove the existence of Dirac Fermions in silicene.
@article{arxiv.1204.2642,
title = {Evidence for Dirac Fermions in a honeycomb lattice based on silicon},
author = {Lan Chen and Cheng-Cheng Liu and Baojie Feng and Xiaoyue He and Peng Cheng and Zijing Ding and Sheng Meng and Yugui Yao and Kehui Wu},
journal= {arXiv preprint arXiv:1204.2642},
year = {2015}
}