2,023 research outputs found
Spatial distribution of local tunneling conductivity due to interference and Coulomb interaction effects for deep and shallow impurities on semiconductor surfaces
Spatial distribution of local tunneling conductivity was investigated for
deep and shallow impurities on semiconductor surfaces. Non-equilibrium Coulomb
interaction and interference effects were taken into account and analyzed
theoretically with the help of Keldysh formalism. Two models were investigated:
mean field self-consistent approach for shallow impurity state and Hubbard-{I}
model for deep impurity state. We have found that not only above the impurity
but also at the distances comparable to the lattice period both effects
interference between direct and resonant tunneling channels and on-site Coulomb
repulsion of localized electrons strongly modifies form of tunneling
conductivity measured by the scanning tunneling microscopy/spectroscopy
(STM/STS).Comment: 5 pages, 3 figure
Spatial effects of Fano resonance in local tunneling conductivity in vicinity of impurity on semiconductor surface
We present the results of local tunneling conductivity spatial distribution
detailed theoretical investigations in vicinity of impurity atom for a wide
range of applied bias voltage. We observed Fano resonance in tunneling
conductivity resulting from interference between resonant tunneling channel
through impurity energy level and direct tunneling channel between the
tunneling contact leads. We have found that interference between tunneling
channels strongly modifies form of tunneling conductivity measured by the
scanning tunneling microscopy/spectroscopy (STM/STS) depending on the distance
value from the impurity.Comment: 4 pages, 3 figure
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