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Disorder Effects Of The Environment Of The Electronic Structure And Transport Properties Of Dna Molecules

Posted on:2012-12-25Degree:MasterType:Thesis
Country:ChinaCandidate:L W LiangFull Text:PDF
GTID:2190330335490973Subject:Physics
Abstract/Summary:PDF Full Text Request
The electrical properties of DNA molecules is one of the research hotspots of multi-science, so far, there are many research results about the electrical properties of DNA, though the researches have achieved some consensus, they still have many contradictory points, so, it is necessary to carry out theoretical studies to find out the mechanism of charge transport which can give some theoretical guidance for the designing and assembling biological molecule devices with special functions.We see the structure of double helix DNA as the quasi one-dimensional molecular chains in this paper, in order to highlight the impact of solution, thermal vibration and other factors in the environment to the structure and electronic properties of charge transport of DNA, we respectively set the central channel as Fibonacci-type DNA or poly G-C DNA molecules which with the potential of skeleton lattice with a different type and degree of disorder, then we study the system's electronic density of states, localization length, the transport coefficients and the electrical properties of volt-ampere characteristic curve, and then we compared the results with the case that does not consider the potential or have ordered lattice skeleton grid potential. Without considering the impact of environmental, the study shows that both kind of DNA have a good degree of degenerate of electronic states, with the increasing of environmental disorder, the peak of electronic states declining, band broadening, and band gap narrowing, all of these showed the features of disordered systems; two types of electronic states of DNA molecules are localized with the disordered conditions, the localization length decreases with the increase of disorder as to the poly GC-DNA molecule, but the localization length of Fibonacci-typ DNA molecules was non-monotonic with the increase of disorder, and the disorder-induced delocalization effect can be observed; two kinds of DNA molecules both have the properties of semiconductor, there is a certain size threshold voltage U of their I-U curves, the threshold voltage decreases monotonically with the degree of disorder increases as to the poly GC-DNA and there is a stable voltage threshold as to the Fibonacci-type DNA.
Keywords/Search Tags:DNA, environment disorder, electronic structure, transport prope
PDF Full Text Request
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