Lifshitz transition across the Ag/Cu(111) superlattice band gap tuned by interface doping

Abstract

5 páginas, 4 figuras.-- PACS numbers: 73.20.At, 73.22.-f, 79.60.Jv ; The two-dimensional, free-electron-like band structure of noble metal surfaces can be radically transformed by appropriate nanostructuration. A case example is the triangular dislocation network that characterizes the epitaxial Ag/Cu(111) system, which exhibits a highly featured band topology with a full band gap above EF and a hole-pocket-like Fermi surface. Here we show that controlled doping of the Ag/Cu(111) interface with Au allows one to observe a complete Lifshitz transition at 300 K; i.e., the hole pockets fill up, the band gap entirely shifts across EF, and the Fermi surface becomes electron-pocket-like. ; This work was supported by the Spanish MICINN (MAT2010-21156-C03-01 and -C03-03) and the Basque Government (IT-257-07). ; Peer reviewed