Continuous Transition from Two- to One-Dimensional States in Si(111)-(5×2)–Au

Abstract

A strong, gold-induced surface state is found on single-domain Si(111)-(5x2)-Au at low temperatures. Its band dispersion is one dimensional near the Fermi level E(F) and gradually becomes two dimensional towards the bottom of the band, thus providing a model for a continuous transition in dimensionality. A Peierls-like gap is observed in the one-dimensional portion of the band near E(F).

Chains of gold atoms with tailored electronic states

“…10,14,23,24 Similar n ϫ1 and nϫ2 reconstructions are formed by deposition of silver, 25 alkali metals, 26,27 alkaline earths, 26,27 and rare earths. 28 However, for flat substrates the length of the chains is limited due to the domain structure imposed by the threefold symmetry of the underlying lattice, which allows three equivalent chain directions (͓1 1 0͔, ͓0 1 1 ͔, ͓1 0 1͔).…”

“…The band gap of silicon prevents metallic states at the Fermi surface from coupling to the substrate both in two dimensions 8,9 and in one dimension. 10,11 The Si͑111͒ surface and its vicinal surfaces ͑see Fig. 1͒ exhibit a natural tendency to form anisotropic reconstructions of metal atoms at the surface.…”

Systematic investigation of the structure of the Si(553)-Au surface from first principles

“…In the case of vicinal substrates, the average terrace width can be controlled by the miscut angle, which provides a route to tuning interwire distances and interactions. 3 Some examples of quasi-one-dimensional reconstructions that have attracted much attention in recent years are the Si͑111͒-͑5 ϫ 2͒-Au, [3][4][5][6][7] Si͑557͒-Au, [8][9][10][11][12][13][14][15][16] Si͑553͒-Au, [17][18][19][20][21][22][23][24] and Si͑111͒-͑4 ϫ 2͒-In ͑Refs. 25-37͒ surfaces.…”

Nature of the broken-symmetry phase of the one-dimensional metallic In/Si(111) surface

“…1 While most of the previous studies on 1D systems have been performed on limited types of anisotropic bulk materials, 1 very recently unique surface 1D metallic systems were identified on the flat and vicinal Si͑111͒ surfaces with atomic-scale chain structures induced by In or Au adsorption. [2][3][4] These systems featuring nearly half-filled 1D electron bands bring about the possibility of detailed investigation of 1D physical properties in nanoscale and of atomic-scale fabrication of tailored 1D materials systems.…”

“…5 A Peierls band gap was introduced for an 1D surface state of Si(111)5ϫ2-Au, 4 which was later discussed to be questionable. 4 The In induced 4ϫ1 chain structure on Si͑111͒ exhibits an ideal 1D Fermi surface and a unique temperature-induced periodicity-doubling phase transition. 2 This system was interpreted as an 1D CDW system driven by Peierls instability.…”