Image-potential states on stepped Cu?(001) surfaces |
| |
Authors: | M Roth M Pickel J Wang M Weinelt Th Fauster |
| |
Institution: | Lehrstuhl für Festk?rperphysik, Universit?t Erlangen-Nürnberg, Staudtstrasse 7, 91058 Erlangen, Germany, DE
|
| |
Abstract: | Image-potential states on Cu (117) and Cu (119) surfaces were studied by means of two-photon photoelectron spectroscopy. The
regular array of steps generates a lateral potential on the vicinal surfaces, which modifies the surface-electronic structure.
Compared to Cu (001), the band bottom of the n=1 image-potential states shifts by 40 meV to lower binding energy. The periodicity
of the step-induced superlattice manifests itself as back-folding of the n=1 and 2 dispersion bands. At the surface Brillouin
zone boundary a mini-gap opens with a width of 135 meV for the first image-potential state on Cu (117). On the vicinal surfaces
the lifetime of the image-potential states is reduced by a factor of three as compared to Cu (001). This is attributed to
a narrowing of the surface-projected bulk-band gap when projected along the 11n] direction. While the dephasing rate of the
first image-potential state is close to the decay rate, higher members of the Rydberg-like series show negligible dephasing.
Received: 16 October 2001 / Revised version: 9 April 2002 / Published online: 6 June 2002 |
| |
Keywords: | PACS: 73 20 At 79 60 Bm |
本文献已被 SpringerLink 等数据库收录! |
|