title: Electrical conductance of DNA molecules with varied density of itinerant pi electrons.
abstract: The electrical transport of DNA is closely related to the density of itinerant pi electrons because of the strong electron-lattice interaction. The resistivities of two typical DNA molecules [poly(dG)-poly(dC) and lambda-DNA] with varied densities of itinerant pi electrons are calculated. It is found that the dependence of the resistivity on the density of itinerant pi electrons is symmetrical about the half-filling state of itinerant pi electrons in poly(dG)-poly(dC). At the half-filling state, the Peierls phase transition takes place and poly(dG)-poly(dC) has a large resistivity. When the density of itinerant pi electrons departs far from the half-filling state, the resistivity of poly(dG)-poly(dC) becomes small. For lambda-DNA, there is no Peierls phase transition due to the aperiodicity of its base pair arrangement. The resistivity of poly(dG)-poly(dC) decreases with increasing length of the molecular chain, but the resistivity of lambda-DNA increases with increasing length. The conducting mechanisms for poly(dG)-poly(dC) and a few lambda-DNA molecules with varied densities of itinerant pi electrons are analyzed.
authors.affiliation: School of Physics and Microelectronics, Shandong University, Jinan 250100, China.
authors.forename: Xu-Tuan
authors.initials: XT
authors.lastname: Gao
authors.forename: Xue
authors.initials: X
authors.lastname: Fu
authors.forename: Liang-Mo
authors.initials: LM
authors.lastname: Mei
authors.forename: Shi-Jie
authors.initials: SJ
authors.lastname: Xie
mesh_terms: D010582:Bacteriophage lambda / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D004279:DNA, Viral / Q000737:chemistry; D004553:Electric Conductivity; D004583:Electrons; D008962:Models, Theoretical
chemical_list: D004279:DNA, Viral; D004247:DNA