中国物理B ›› 2013, Vol. 22 ›› Issue (11): 117303-117303.doi: 10.1088/1674-1056/22/11/117303

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

Thermoelectric transport through a quantum dot with a magnetic impurity

于震a, 郭宇b, 郑军a c, 迟锋b   

  1. a College of Engineering, Bohai University, Jinzhou 121013, China;
    b School of Mathematics and Physics, Bohai University, Jinzhou 121013, China;
    c State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • 收稿日期:2013-04-07 修回日期:2013-05-24 出版日期:2013-09-28 发布日期:2013-09-28
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 61274101) and the SKLSM (Grant No. CHJG200901).

Thermoelectric transport through a quantum dot with a magnetic impurity

Yu Zhen (于震)a, Guo Yu (郭宇)b, Zheng Jun (郑军)a c, Chi Feng (迟锋)b   

  1. a College of Engineering, Bohai University, Jinzhou 121013, China;
    b School of Mathematics and Physics, Bohai University, Jinzhou 121013, China;
    c State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • Received:2013-04-07 Revised:2013-05-24 Online:2013-09-28 Published:2013-09-28
  • Contact: Chi Feng E-mail:chifeng@semi.ac.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 61274101) and the SKLSM (Grant No. CHJG200901).

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摘要： We study the thermoelectric effect in a small quantum dot with a magnetic impurity in the Coulomb blockade regime. The electrical conductance, thermal conductance, thermopower, and the thermoelectrical figure of merit (FOM) are calculated by using Green’s function method. It is found that the peaks in the electrical conductance are split by the exchange coupling between the electron entering into the dot and the magnetic impurity inside the dot, accompanied by the decrease in the height of peaks. As a result, the resonances in the thermoelectric quantities, such as the thermal conductance, thermopower, and the FOM, are all split, opening some effective new working regions. Despite of the significant reduction in the height of the electrical conductance peaks induced by the exchange coupling, the values of the FOM and the thermopower can be as large as those in the case of zero exchange coupling. We also find that the thermoelectric efficiency, characterized by the magnitude of the FOM, can be enhanced by adjusting the left–right asymmetry of the electrode–dot coupling or by optimizing the system’s temperature.

关键词: quantum dot, thermoelectric effect, magnetic impurity

Abstract: We study the thermoelectric effect in a small quantum dot with a magnetic impurity in the Coulomb blockade regime. The electrical conductance, thermal conductance, thermopower, and the thermoelectrical figure of merit (FOM) are calculated by using Green’s function method. It is found that the peaks in the electrical conductance are split by the exchange coupling between the electron entering into the dot and the magnetic impurity inside the dot, accompanied by the decrease in the height of peaks. As a result, the resonances in the thermoelectric quantities, such as the thermal conductance, thermopower, and the FOM, are all split, opening some effective new working regions. Despite of the significant reduction in the height of the electrical conductance peaks induced by the exchange coupling, the values of the FOM and the thermopower can be as large as those in the case of zero exchange coupling. We also find that the thermoelectric efficiency, characterized by the magnitude of the FOM, can be enhanced by adjusting the left–right asymmetry of the electrode–dot coupling or by optimizing the system’s temperature.

Key words: quantum dot, thermoelectric effect, magnetic impurity

中图分类号:  (Quantum dots)

  • 73.21.La
72.15.Jf (Thermoelectric and thermomagnetic effects) 73.50.Lw (Thermoelectric effects)