2,781 research outputs found
Single molecule DNA sequencing via transverse electronic transport using a graphene nanopore: A tight-binding approach
We report a tight-binding model study of two-terminal graphene nanopore based
device, for sequential determination of DNA bases. Using Greens function
approach we calculate conductance spectra, I-V response and also the changes in
local density of states (LDOS) profile as four different nucleobases inserted
one by one into the pore embedded in the zigzag graphene nanoribbon (ZGNR). We
find distinct features in LDOS profile for different nucleotides and the same
is also present in conductance and I-V response. We propose the actual working
principle of the device, by setting the bias across the pore to a fixed voltage
(this voltage gives maximum discrimination between characteristic current of
the four nucleotides) and translocating the ss-DNA through the nanopore using a
transverse electric field while recording the characteristic current of the
nucleotides. Not only the typical current output is much larger than previous
results, but the seaparation between them for different bases are also
definite. Our investigation provides high accuracy and significant amount of
distinction between different nucleotides.Comment: 6 pages, 5 figure
Ground state phase diagram and magnetoconductance of a one-dimensional Hubbard superlattice at half-filling
We have studied a one dimensional Hubbard superlattice with different Coulomb
correlations at alternating sites for a half-filled band. Mean field
calculations based on the Hartree-Fock approximation together with a real space
renormalization group technique were used to study the ground state of the
system. The phase diagrams obtained in these approaches agree with each other
from the weak to the intermediate coupling regime. The mean field results show
very quick convergence with system size. The renormalization group results
indicate a spatial modulation of local moments that was identified in some
previous work. Also we have studied the magnetoconductance of such
superlattices which reveals several interesting points.Comment: 10 pages, 13 figures. to be published in Phys. Rev. B, vol. 75, Issue
23 (tentative
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