中国物理B ›› 2009, Vol. 18 ›› Issue (8): 3591-3596.doi: 10.1088/1674-1056/18/8/076

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Characteristics of alternating current hopping conductivity in DNA sequences

马松山1, 徐慧1, 郭锐1, 王焕友2   

  1. (1)School of Physical Science and Technology, Central South University, Changsha 410083, China; (2)School of Physical Science and Technology, Central South University, Changsha 410083, China;Department of Physics, Xiangnan University, Chenzhou \rm 423000, China
  • 收稿日期:2009-01-03 修回日期:2009-01-19 出版日期:2009-08-20 发布日期:2009-08-20
  • 基金资助:
    Project supported by the Doctoral Program Foundation of Institutions of Higher Education, China (Grant No 20070533075).

Characteristics of alternating current hopping conductivity in DNA sequences

Ma Song-Shan(马松山)a)†, Xu Hui(徐慧)a), Wang Huan-You(王焕友)a)b), and Guo Rui(郭锐)a)   

  1. a School of Physical Science and Technology, Central South University, Changsha 410083, China; b Department of Physics, Xiangnan University, Chenzhou 423000, China
  • Received:2009-01-03 Revised:2009-01-19 Online:2009-08-20 Published:2009-08-20
  • Supported by:
    Project supported by the Doctoral Program Foundation of Institutions of Higher Education, China (Grant No 20070533075).

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摘要： This paper presents a model to describe alternating current (AC) conductivity of DNA sequences, in which DNA is considered as a one-dimensional (1D) disordered system, and electrons transport via hopping between localized states. It finds that AC conductivity in DNA sequences increases as the frequency of the external electric field rises, and it takes the form of σac (ω)～ω 2\ln 2(1/ω). Also AC conductivity of DNA sequences increases with the increase of temperature, this phenomenon presents characteristics of weak temperature-dependence. Meanwhile, the AC conductivity in an off-diagonally correlated case is much larger than that in the uncorrelated case of the Anderson limit in low temperatures, which indicates that the off-diagonal correlations in DNA sequences have a great effect on the AC conductivity, while at high temperature the off-diagonal correlations no longer play a vital role in electric transport. In addition, the proportion of nucleotide pairs p also plays an important role in AC electron transport of DNA sequences. For p < 0.5, the conductivity of DNA sequence decreases with the increase of p, while for p ≥ 0.5, the conductivity increases with the increase of p.

Abstract: This paper presents a model to describe alternating current (AC) conductivity of DNA sequences, in which DNA is considered as a one-dimensional (1D) disordered system, and electrons transport via hopping between localized states. It finds that AC conductivity in DNA sequences increases as the frequency of the external electric field rises, and it takes the form of $\sigma_{\rm ac}(\omega)\sim \omega^2 \ln^2(1/\omega)$. Also AC conductivity of DNA sequences increases with the increase of temperature, this phenomenon presents characteristics of weak temperature-dependence. Meanwhile, the AC conductivity in an off-diagonally correlated case is much larger than that in the uncorrelated case of the Anderson limit in low temperatures, which indicates that the off-diagonal correlations in DNA sequences have a great effect on the AC conductivity, while at high temperature the off-diagonal correlations no longer play a vital role in electric transport. In addition, the proportion of nucleotide pairs p also plays an important role in AC electron transport of DNA sequences. For p < 0.5, the conductivity of DNA sequence decreases with the increase of p, while for p ≥ 0.5, the conductivity increases with the increase of p.

Key words: DNA sequences, AC hopping conductivity, off-diagonal correlations

中图分类号:  (Colloids)

  • 82.70.Dd
47.57.J- (Colloidal systems)