中国物理B ›› 2004, Vol. 13 ›› Issue (1): 95-99.doi: 10.1088/1009-1963/13/1/018

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Transmission of electron through an Aharonov－Bohm interferometer with a quantum dot in Coulomb blockade regime

孙科伟, 熊诗杰   

  1. State Key Laboratory of Solid State Microstructure and Department of Physics, Nanjing University, Nanjing 210093, China
  • 收稿日期:2003-04-15 修回日期:2003-05-30 出版日期:2004-01-22 发布日期:2007-03-22
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10074029 and 60276005), and the State Key Program of Basic Research of China (Grant No G1999064509).

Transmission of electron through an Aharonov－Bohm interferometer with a quantum dot in Coulomb blockade regime

Sun Ke-Wei (孙科伟), Xiong Shi-Jie (熊诗杰)   

  1. State Key Laboratory of Solid State Microstructure and Department of Physics, Nanjing University, Nanjing 210093, China
  • Received:2003-04-15 Revised:2003-05-30 Online:2004-01-22 Published:2007-03-22
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10074029 and 60276005), and the State Key Program of Basic Research of China (Grant No G1999064509).

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摘要： We calculate conductance of an Aharonov－Bohm (AB) interferometer for which a single-level quantum dot in the Coulomb blockade regime is embedded in one of its arms. Using the Schr?dinger equations and taking into account the Coulomb interaction on the dot, we calculate conductance G as a function of flux φ threaded through the ring and as a function of gate voltage V applied to the dot. It is found that the AB oscillations of G(φ) depend on the particle occupation on the dot, controlled by V. If the system is closed, there is no loss of particles, G(φ) is periodic and G(φ)=G(-φ), satisfying the Onsager relation. In this case G(φ) can reach its maximum value, 2e^2/h, at the resonance. When the system is open, one has G(φ)≠G(-φ), G(φ) yields a phase shift which depends on the loss rate of electrons in this open system.

关键词: Aharonov－Bohm interferometer, quantum dot, Coulomb blockade

Abstract: We calculate conductance of an Aharonov－Bohm (AB) interferometer for which a single-level quantum dot in the Coulomb blockade regime is embedded in one of its arms. Using the Schr?dinger equations and taking into account the Coulomb interaction on the dot, we calculate conductance G as a function of flux $\phi$ threaded through the ring and as a function of gate voltage V applied to the dot. It is found that the AB oscillations of $G(\phi)$ depend on the particle occupation on the dot, controlled by V. If the system is closed, there is no loss of particles, $G(\phi)$ is periodic and $G(\phi)=G(-\phi)$, satisfying the Onsager relation. In this case $G(\phi)$ can reach its maximum value, $2e^2/h$, at the resonance. When the system is open, one has $G(\phi)≠G(-\phi)$, $G(\phi)$ yields a phase shift which depends on the loss rate of electrons in this open system.

Key words: Aharonov－Bohm interferometer, quantum dot, Coulomb blockade

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

  • 73.23.Hk
73.63.Kv (Quantum dots) 73.21.La (Quantum dots) 03.65.Ge (Solutions of wave equations: bound states) 03.65.Ta (Foundations of quantum mechanics; measurement theory)