The two-dimensional, free-electron-like band structure of noble metal surfaces can be radicallytransformed by appropriate nanostructuration. A case example is the 2D triangular dislocation networkthat characterizes the epitaxial Ag/Cu(111) system, which exhibits a highly featured band topology with afull band gap above EF and a hole-pocket-like Fermi surface. We will show that controlled doping of theAg/Cu(111) interface with Au allows one to observe a complete Lifshitz transition at 300 K; i.e., the holepockets fill up, the band gap entirely shifts across EF, and the Fermi surface becomes electron-pocket-like.Likewise, surfaces with periodic array of 1D steps, namely vicinal surfaces, exhibit Fermi gap openings when the periodicity is tuned to the substrate’s Fermi wavevector. We will show that at such distinct periodicities there exists geometrical/electronic structure interplay. At the end we combine both the 2D dislocation lattice with the 1D step array on the Ag/v-Cu(111). We obtained highly featured surface states with coexisting dislocation and step gaps. Such nanopatterned surfaces are good candidatesto explore new plasmonic-like phenomena within the context of “surface state nanoelectronics”.


Seminar, September 10, 2014, 15:00. Seminar Room

Hosted by Prof. Javier García de Abajo