4,595 research outputs found
Electric Transport Theory of Dirac Fermions in Graphene
Using the self-consistent Born approximation to the Dirac fermions under
finite-range impurity scatterings, we show that the current-current correlation
function is determined by four-coupled integral equations. This is very
different from the case for impurities with short-range potentials. As a test
of the present approach, we calculate the electric conductivity in graphene for
charged impurities with screened Coulomb potentials. The obtained conductivity
at zero temperature varies linearly with the carrier concentration, and the
minimum conductivity at zero doping is larger than the existing theoretical
predictions, but still smaller than that of the experimental measurement. The
overall behavior of the conductivity obtained by the present calculation at
room temperature is similar to that at zero temperature except the minimum
conductivity is slightly larger.Comment: 6 pages, 3 figure
Gauge invariant nonlinear electric transport in mesoscopic conductors
We use the scattering approach to investigate the nonlinear current-voltage
characteristic of mesoscopic conductors. We discuss the leading nonlinearity by
taking into account the self-consistent nonequilibrium potential. We emphasize
conservation of the overall charge and current which are connected to the
invariance under a global voltage shift (gauge invariance). As examples, we
discuss the rectification coefficient of a quantum point contact and the
nonlinear current-voltage characteristic of a resonant level in a double
barrier structure.Comment: (Replaced version, with corrected Eq.(4)); 5 pages, RevTeX, 1 figure,
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The Predominance of Electric Transport in Synaptic Transmission
The quantitative description of the motion of neurotransmitters in the synaptic cleft appears to be one of the most difficult problems in the modeling of synapses. Here we show in contradiction to the common view, that this process is merely governed by electric transport than diffusion forces
Characteristic Length Scale of Electric Transport Properties of Genomes
A tight-binding model together with a novel statistical method are used to
investigate the relation between the sequence-dependent electric transport
properties and the sequences of protein-coding regions of complete genomes. A
correlation parameter is defined to analyze the relation. For some
particular propagation length , the transport behaviors of the coding
and non-coding sequences are very different and the correlation reaches its
maximal value . and \omax are characteristic values for
each species. The possible reason of the difference between the features of
transport properties in the coding and non-coding regions is the mechanism of
DNA damage repair processes together with the natural selection.Comment: 4 pages, 4 figure
Strong dopant dependence of electric transport in ion-gated MoS2
We report modifications of the temperature-dependent transport properties of
thin flakes via field-driven ion intercalation in an electric
double layer transistor. We find that intercalation with ions
induces the onset of an inhomogeneous superconducting state. Intercalation with
leads instead to a disorder-induced incipient metal-to-insulator
transition. These findings suggest that similar ionic species can provide
access to different electronic phases in the same material.Comment: 5 pages, 3 figure
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