中国物理B ›› 2014, Vol. 23 ›› Issue (5): 57302-057302.doi: 10.1088/1674-1056/23/5/057302

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

Phonon-dependent transport through a serially coupled double quantum dot system

M. Bagheri Tagani, H. Rahimpour Soleimani   

  1. Department of Physics, University of Guilan, P. O. Box 41335-1914, Rasht, Iran
  • 收稿日期:2013-10-14 修回日期:2013-11-28 出版日期:2014-05-15 发布日期:2014-05-15

Phonon-dependent transport through a serially coupled double quantum dot system

M. Bagheri Tagani, H. Rahimpour Soleimani   

  1. Department of Physics, University of Guilan, P. O. Box 41335-1914, Rasht, Iran
  • Received:2013-10-14 Revised:2013-11-28 Online:2014-05-15 Published:2014-05-15
  • Contact: H. Rahimpour Soleimani E-mail:rahimpour@guilan.ac.ir
  • About author:73.23.Hk; 73.63.Kv

摘要: Using Keldysh nonequilibrium Green function formalism and mapping a many-body electron-phonon interaction onto a one body problem, the electron transport through a serially coupled double quantum dot system is analyzed. The influence of the electron-phonon interaction, temperature, detuning, and interdot tunneling on the transmission coefficient and current is studied. Our results show that the electron-phonon interaction results in the appearance of the side peaks in the transmission coefficient, whose height is strongly dependent on the phonon temperature. We have also found that the inequality of the electron-phonon interaction strength in two dots gives rise to an asymmetry in the current-voltage characteristic. In addition, the temperature difference between the phonon and electron subsystems results in the reduction of the saturated current and the destruction of the step-like behavior of the current. It is also observed that the detuning can improve the magnitude of the current by compensating the mismatch of the quantum dots energy levels induced by the electron-phonon interaction.

关键词: quantum dot, electron-phonon interaction, Keldysh nonequilibrium Green function formalism, current-voltage characteristic

Abstract: Using Keldysh nonequilibrium Green function formalism and mapping a many-body electron-phonon interaction onto a one body problem, the electron transport through a serially coupled double quantum dot system is analyzed. The influence of the electron-phonon interaction, temperature, detuning, and interdot tunneling on the transmission coefficient and current is studied. Our results show that the electron-phonon interaction results in the appearance of the side peaks in the transmission coefficient, whose height is strongly dependent on the phonon temperature. We have also found that the inequality of the electron-phonon interaction strength in two dots gives rise to an asymmetry in the current-voltage characteristic. In addition, the temperature difference between the phonon and electron subsystems results in the reduction of the saturated current and the destruction of the step-like behavior of the current. It is also observed that the detuning can improve the magnitude of the current by compensating the mismatch of the quantum dots energy levels induced by the electron-phonon interaction.

Key words: quantum dot, electron-phonon interaction, Keldysh nonequilibrium Green function formalism, current-voltage characteristic

中图分类号:  (Coulomb blockade; single-electron tunneling)

  • 73.23.Hk
73.63.Kv (Quantum dots)