Connection between electronic structure and inter-atomic potentials for Si(111)5x2-Au

The Si(111)5× 2-Au surface has been studied extensively because of its one-dimensional structure and its application in an atomic scale memory [1], where the storage density limit is determined by inter-atomic coupling [2]. In an effort to establish a connection between the electronic structure and the inter-atomic potentials we present an angle-resolved photoemission study of single domain 5× 2 in the vicinity of the Fermi level E_F [3]. The density of states near E_F exhibits peaks in the momentum distribution curves that correspond to zone boundaries a 5× 4 unit cell. The opening of a gap at these k-points is able to stabilize a 5× 4 lattice, which indeed has been observed for the Si adatoms that store the bits [1] and for their inter-atomic potentials [2]. The same atoms are responsible for optimal band filling [4]. 1. R. Bennnewitz et.al., Nanotech. 13, 499 (2002). 2. A. Kirakosian et.al., Phys. Rev. B. 67, 205412 (2003). 3. J. L. McChesney et.al., submitted to Phys. Rev. B. 4. S. C. Erwin, Phys. Rev. Lett. 91, 206101 (2003).