Electronic structure of Ge(111)-(2×1) surface in the presence of doping atoms. Ab initio analysis of STM data
S. V. Savinov, S. I. Oreshkin*, N. S. Maslova
Moscow State University, Dpt. of Physics, 119991 Moscow, Russia
*Moscow State University, Sternberg Astronomical Institute, 119991 Moscow, Russia
Abstract
We present the result of first principles modeling of the
Ge(111)-(2×1) surface electronic structure in the presence of donor
doping atom at certain position in the surface bi-layer of (2×1) reconstruction.
We briefly compare these results with the data of experimental low temperature
STM investigations.
Ab initio calculations demonstrate that doping atom strongly disturbs
local electronic structure. The separate state, most probably split off
conduction band, appears in the bandgap. Surface LDOS reveals spatial
oscillations in vicinity of foreign atom.
We also show that the spatial extent of non-negligible inter-atomic
interaction between neighboring donor atoms is not less then 70 Å.