title: Origin of p(2 x 1) phase on Si(001) by noncontact atomic force microscopy at 5 k.
abstract: The controversial issue of the origin of the p(2 x 1) reconstruction of the Si(001) surface observed in recent low temperature scanning tunneling microscopy experiments is clarified here using 5 K noncontact atomic force microscopy. The c(4 x 2) phase is observed at separations corresponding to weak tip-surface interactions, confirming that it is the ground state of the surface. At larger frequency shifts the p(2 x 1) phase of symmetric dimers is observed. By studying the interaction of a reactive Si tip with the c(4 x 2) Si(001) surface using an ab initio method, we find that the observed change in the surface reconstruction is an apparent effect caused by tip induced dimer flipping resulting in a modification of the surface structure and appearance of the p(2 x 1) phase in the image. Using an appropriate scanning protocol, one can manipulate the surface reconstruction at will, which has significance in nanotechnology.
authors.affiliation: Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Yan Jun
authors.initials: YJ
authors.lastname: Li
authors.forename: Hikaru
authors.initials: H
authors.lastname: Nomura
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Ozaki
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Naitoh
authors.forename: Masami
authors.initials: M
authors.lastname: Kageshima
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sugawara
authors.forename: Chris
authors.initials: C
authors.lastname: Hobbs
authors.forename: Lev
authors.initials: L
authors.lastname: Kantorovich