中国物理B ›› 2015, Vol. 24 ›› Issue (6): 67307-067307.doi: 10.1088/1674-1056/24/6/067307

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Stability of conductance oscillations in carbon atomic chains

于景新, 侯志伟, 刘秀英   

  1. College of Science, Henan University of Technology, Zhengzhou 450001, China
  • 收稿日期:2014-11-20 修回日期:2015-01-05 出版日期:2015-06-05 发布日期:2015-06-05
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11304079, 11404094, and 51201059), the Priority Scientific and Technological Project of Henan Province, China (Grant No. 14A140027), the School Fund (Grant No. 2012BS055), and the Plan of Natural Science Fundamental Research of Henan University of Technology, China (Grant No. 2014JCYJ15).

Stability of conductance oscillations in carbon atomic chains

Yu Jing-Xin (于景新), Hou Zhi-Wei (侯志伟), Liu Xiu-Ying (刘秀英)   

  1. College of Science, Henan University of Technology, Zhengzhou 450001, China
  • Received:2014-11-20 Revised:2015-01-05 Online:2015-06-05 Published:2015-06-05
  • Contact: Yu Jing-Xin E-mail:j.x.yu@qq.com
  • About author:73.63.Rt; 61.46.-w; 71.15.Mb
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11304079, 11404094, and 51201059), the Priority Scientific and Technological Project of Henan Province, China (Grant No. 14A140027), the School Fund (Grant No. 2012BS055), and the Plan of Natural Science Fundamental Research of Henan University of Technology, China (Grant No. 2014JCYJ15).

摘要: The conductance stabilities of carbon atomic chains (CACs) with different lengths are investigated by performing theoretical calculations using the nonequilibrium Green's function method combined with density functional theory. Regular even–odd conductance oscillation is observed as a function of the wire length. This oscillation is influenced delicately by changes in the end carbon or sulfur atoms as well as variations in coupling strength between the chain and leads. The lowest unoccupied molecular orbital in odd-numbered chains is the main transmission channel, whereas the conductance remains relatively small for even-numbered chains and a significant drift in the highest occupied molecular orbital resonance toward higher energies is observed as the number of carbon atoms increases. The amplitude of the conductance oscillation is predicted to be relatively stable based on a thiol joint between the chain and leads. Results show that the current–voltage evolution of CACs can be affected by the chain length. The differential and second derivatives of the conductance are also provided.

关键词: electronic transport, density functional theory, non-equilibrium Green', s function, carbon atomic chains

Abstract: The conductance stabilities of carbon atomic chains (CACs) with different lengths are investigated by performing theoretical calculations using the nonequilibrium Green's function method combined with density functional theory. Regular even–odd conductance oscillation is observed as a function of the wire length. This oscillation is influenced delicately by changes in the end carbon or sulfur atoms as well as variations in coupling strength between the chain and leads. The lowest unoccupied molecular orbital in odd-numbered chains is the main transmission channel, whereas the conductance remains relatively small for even-numbered chains and a significant drift in the highest occupied molecular orbital resonance toward higher energies is observed as the number of carbon atoms increases. The amplitude of the conductance oscillation is predicted to be relatively stable based on a thiol joint between the chain and leads. Results show that the current–voltage evolution of CACs can be affected by the chain length. The differential and second derivatives of the conductance are also provided.

Key words: electronic transport, density functional theory, non-equilibrium Green's function, carbon atomic chains

中图分类号:  (Nanoscale contacts)

  • 73.63.Rt
61.46.-w (Structure of nanoscale materials) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)