Dirac Fermions in Blue Phosphorene Monolayer

International audience; 2D materials beyond graphene and in particular 2D semiconductors haveraised interest due to their unprecedented electronic properties, such as highcarrier mobility or tunable bandgap. Blue phosphorene is an allotrope of blackphosphorene that resembles graphene as it presents a honeycomb structure.However, it is known to have semiconductor character and the crucial pointis to determine whether this hexagonal phase of phosphorene presents Diracfermions as in graphene. Here, the first compelling experimental evidenceof Dirac fermions in blue phosphorene layer grown on Cu(111) surface ispresented. The results highlight the formation of a highly ordered bluephosphorene sheet with a clear Dirac cone at the high symmetry points of theBrillouin Zone. The charge carriers behave as massless relativistic particles.Therefore, all the expectations held for graphene, such as high-speed electronicdevices based on ballistic transport at room temperature, may also beapplied to blue phosphorene.