Evidence of Dirac fermions in multilayer silicene

Multilayer silicene, the silicon analogue of multilayer graphene, grown on silver (111) surfaces, possesses a honeycomb (33)R30 reconstruction, observed by scanning tunnelling microscopy at room temperature, past the initial formation of the dominant, 33 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. p* and p states meet at 0.25 eV below the Fermi level, providing clear evidence of the presence of gapless Dirac fermions.