Evidence of Dirac fermions in multilayer silicene

Multilayer silicene, the silicon analogue of multilayer graphene, grown on silver (111) surfaces, possesses a honeycomb (root 3 x root 3)R30 degrees reconstruction, observed by scanning tunnelling microscopy at room temperature, past the initial formation of the dominant, 3 x 3 reconstructed, silicene monolayer. For a few layers silicene film we measure by synchrotron radiation photoelectron spectroscopy, a cone-like dispersion at the Brillouin zone centre due to band folding. pi* and pi states meet at similar to 0.25 eV below the Fermi level, providing clear evidence of the presence of gapless Dirac fermions. (C) 2013 AIP Publishing LLC [http://dx.doi.org/10.1063/1.4802782]