Itinerant electron model and conductance of DNA
ABSTRACT DNA (Deoxyribonucleic acid) has recently caught the attention of chemists and physicists. A major reason for this interest
is DNA’s potential use in nanoelectronic devices, both as a template for assembling nanocircuits and as an element of such
circuits. However, the electronic properties of the DNA molecule remain very controversial. Charge-transfer reactions and
conductivity measurements show a large variety of possible electronic behavior, ranging from Anderson and band-gap insulators
to effective molecular wires and induced superconductors. In this review article, we summarize the wide-ranging experimental
and theoretical results of charge transport in DNA. An itinerant electron model is suggested and the effect of the density
of itinerant electrons on the conductivity of DNA is studied. Calculations show that a DNA molecule may show conductivity
from insulating to metallic, which explains the controversial and profuse electric characteristics of DNA to some extent.
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Article: Polarons and conduction in DNA[show abstract] [hide abstract]
ABSTRACT: Using a simple model for the interaction of an extra electron or hole with the vibrations of the DNA stack, we calculate energies and wavefunctions of trapped holes, the properties of large polarons, including the effect of the water and counterions surrounding DNA, and the role of polarons in diffusion and conduction in DNA.Synthetic Metals 01/2003; 137:1381-1383. · 2.11 Impact Factor
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ABSTRACT: It has been known that a charged polaron will reach a constant speed after being accelerated only for a short time in an electric field. Within a dynamical nonadiabatic evolution method, we simulate the motion of polaron under the influence of the electric field which is present for different periods. We find the lattice oscillation behind the polaron will be localized and separated with the moving polaron once the electric field is turned off. It is shown that the localized lattice oscillation is nothing but a breather, specifically, a moving multibreather excitation. Furthermore, it is the breather which bears the incresed energy due to the electric field acting on the polaron, so that the polaron can move at a constant speed even in the presence of an electric field.Physical review. B, Condensed matter 01/2004; 70(6).
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ABSTRACT: The semiconductor industry has seen a remarkable miniaturization trend, driven by many scientific and technological innovations. But if this trend is to continue, and provide ever faster and cheaper computers, the size of microelectronic circuit components will soon need to reach the scale of atoms or molecules--a goal that will require conceptually new device structures. The idea that a few molecules, or even a single molecule, could be embedded between electrodes and perform the basic functions of digital electronics--rectification, amplification and storage--was first put forward in the mid-1970s. The concept is now realized for individual components, but the economic fabrication of complete circuits at the molecular level remains challenging because of the difficulty of connecting molecules to one another. A possible solution to this problem is 'mono-molecular' electronics, in which a single molecule will integrate the elementary functions and interconnections required for computation.Nature 12/2000; 408(6812):541-8. · 38.60 Impact Factor