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Title: Tunneling spectroscopy of a phosphorus impurity atom on the Ge(111)-(2 × 1) surface

We numerically model the Ge(111)-(2 × 1) surface electronic properties in the vicinity of a P donor impurity atom located near the surface. We find a notable increase in the surface local density of states (LDOS) around the surface dopant near the bottom of the empty surface state band π*, which we call a split state due to its limited spatial extent and energetic position inside the band gap. We show that despite the well-established bulk donor impurity energy level position at the very bottom of the conduction band, a surface donor impurity on the Ge(111)-(2 × 1) surface might produce an energy level below the Fermi energy, depending on the impurity atom local environment. It is demonstrated that the impurity located in subsurface atomic layers is visible in a scanning tunneling microscope (STM) experiment on the Ge(111)-(2 × 1) surface. The quasi-1D character of the impurity image, observed in STM experiments, is confirmed by our computer simulations with a note that a few π-bonded dimer rows may be affected by the presence of the impurity atom. We elaborate a model that allows classifying atoms on the experimental low-temperature STM image. We show the presence of spatial oscillations of themore » LDOS by the density-functional theory method.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. Moscow State University (Russian Federation)
  2. Moscow State University, Sternberg Astronomical Institute (Russian Federation)
  3. Laboratorium voor Stoffysica en Magnetisme (Belgium)
Publication Date:
OSTI Identifier:
22472217
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 120; Journal Issue: 6; Other Information: Copyright (c) 2015 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ATOMS; COMPUTERIZED SIMULATION; DENSITY FUNCTIONAL METHOD; DENSITY OF STATES; DIMERS; ELECTRONIC STRUCTURE; ENERGY LEVELS; GERMANIUM; IMPURITIES; LAYERS; OSCILLATIONS; PHOSPHORUS; SCANNING TUNNELING MICROSCOPY; SPECTROSCOPY; SURFACES; TUNNEL EFFECT