中国物理B ›› 2005, Vol. 14 ›› Issue (10): 2093-2099.doi: 10.1088/1009-1963/14/10/028

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Ac response of a coupled double quantum dot

徐婕1, 詹士昌1, W.Z.Shangguan2   

  1. (1)Department of Physics, Institute of Microfluidic Chip, Hangzhou Teacher's College, Hangzhou 310012, China; (2)School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798
  • 收稿日期:2005-03-29 修回日期:2005-06-01 出版日期:2005-10-20 发布日期:2005-10-20

Ac response of a coupled double quantum dot

Xu Jie (徐婕)a, Shangguan W. Z.b, Zhan Shi-Chang (詹士昌)a   

  1. a Department of Physics, Institute of Microfluidic Chip, Hangzhou Teacher's College, Hangzhou 310012, China; b School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798
  • Received:2005-03-29 Revised:2005-06-01 Online:2005-10-20 Published:2005-10-20

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摘要： The effect of phase-breaking process on the ac response of a coupled double quantum dot is studied in this paper based on the nonequilibrium Green function formalism. A general expression is derived for the ac current in the presence of electron--phonon interaction. The ac conductance is numerically computed and the results are compared with those in [Anatram M P and Datta S 1995 Phys. Rev. B 51 7632]. Our results reveal that the inter-dot electron tunnelling interplays with that between dots and electron reservoirs, and contributes prominently to the ac current when inter-dot tunnelling coupling is much larger than the tunnelling coupling between dots and electron reservoirs. In addition, the phase-breaking process is found to have a significant effect on the ac transport through the coupled double dot.

关键词: electronic transport, electron-phonon interaction, differential conductance, Keldysh Green's function

Abstract: The effect of phase-breaking process on the ac response of a coupled double quantum dot is studied in this paper based on the nonequilibrium Green function formalism. A general expression is derived for the ac current in the presence of electron--phonon interaction. The ac conductance is numerically computed and the results are compared with those in [Anatram M P and Datta S 1995 Phys. Rev. B 51 7632]. Our results reveal that the inter-dot electron tunnelling interplays with that between dots and electron reservoirs, and contributes prominently to the ac current when inter-dot tunnelling coupling is much larger than the tunnelling coupling between dots and electron reservoirs. In addition, the phase-breaking process is found to have a significant effect on the ac transport through the coupled double dot.

Key words: electronic transport, electron-phonon interaction, differential conductance, Keldysh Green's function

中图分类号:  (Scattering by phonons, magnons, and other nonlocalized excitations)

  • 72.10.Di
63.20.K- (Phonon interactions) 73.21.La (Quantum dots)