Electrical conductance of DNA molecules with varied density of itinerant pi electrons.
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.
Gao
Xu-Tuan
XT
School of Physics and Microelectronics, Shandong University, Jinan 250100, China.
Fu
Xue
X
Mei
Liang-Mo
LM
Xie
Shi-Jie
SJ
D010582:Bacteriophage lambda / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D004279:DNA, Viral / Q000737:chemistry; D004553:Electric Conductivity; D004583:Electrons; D008962:Models, Theoretical
D004279:DNA, Viral; D004247:DNA