453 research outputs found
On strictly Deza graphs with parameters (n,k,k-1,a)
A nonempty -regular graph on vertices is called a Deza graph
if there exist constants and such that any pair of
distinct vertices of has precisely either or common
neighbours. The quantities , , , and are called the parameters of
and are written as the quadruple . If a Deza graph has
diameter 2 and is not strongly regular, then it is called a strictly Deza
graph. In the paper we investigate strictly Deza graphs with parameters , where its quantities satisfy the conditions and
.Comment: Any comments or suggestions are very welcom
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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