中国物理B ›› 2012, Vol. 21 ›› Issue (7): 77301-077301.doi: 10.1088/1674-1056/21/7/077301

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

Generating and reversing spin accumulation by temperature gradient in a quantum dot attached to ferromagnetic leads

白旭芳a, 迟锋b, 郑军c, 李亦楠b   

  1. a College of Physics and Electronic Information, Inner Mongolia National University, Tongliao 028043, China;
    b College of Engineering, Bohai University, Jinzhou 121013, China;
    c SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • 收稿日期:2011-12-07 修回日期:2011-12-31 出版日期:2012-06-01 发布日期:2012-06-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 10704011), the SKLSM, China (Grant No. CHJG200901), and the LNET, China (Grant No. 2009R01).

Generating and reversing spin accumulation by temperature gradient in a quantum dot attached to ferromagnetic leads

Bai Xu-Fang(白旭芳)a), Chi Feng(迟锋) b)†, Zheng Jun(郑军)c), and Li Yi-Nan(李亦楠)b)   

  1. a College of Physics and Electronic Information, Inner Mongolia National University, Tongliao 028043, China;
    b College of Engineering, Bohai University, Jinzhou 121013, China;
    c SKLSM, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • Received:2011-12-07 Revised:2011-12-31 Online:2012-06-01 Published:2012-06-01
  • Contact: Chi Feng E-mail:chifeng@semi.ac.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 10704011), the SKLSM, China (Grant No. CHJG200901), and the LNET, China (Grant No. 2009R01).

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摘要： We propose to generate and reverse the spin accumulation in a quantum dot (QD) by using the temperature difference between the two ferromagnetic leads connected to the dot. The electrons are driven purely by the temperature gradient in the absence of electric bias and magnetic field. In the Coulomb blockade regime, we find two ways to reverse the spin accumulation. One is by adjusting the QD energy level with a fixed temperature gradient, and the other is by reversing the temperature gradient direction for a fixed value of the dot level. The spin accumulation in the QD can be enhanced by the magnitudes of both the leads' spin polarization and the asymmetry of the dot--lead coupling strengths. The present device is quite simple, and the obtained results may have practical usage in spintronics or quantum information processing.

关键词: quantum dot, temperature gradient, spin accumulation, ferromagnetic leads

Abstract: We propose to generate and reverse the spin accumulation in a quantum dot (QD) by using the temperature difference between the two ferromagnetic leads connected to the dot. The electrons are driven purely by the temperature gradient in the absence of electric bias and magnetic field. In the Coulomb blockade regime, we find two ways to reverse the spin accumulation. One is by adjusting the QD energy level with a fixed temperature gradient, and the other is by reversing the temperature gradient direction for a fixed value of the dot level. The spin accumulation in the QD can be enhanced by the magnitudes of both the leads' spin polarization and the asymmetry of the dot--lead coupling strengths. The present device is quite simple, and the obtained results may have practical usage in spintronics or quantum information processing.

Key words: quantum dot, temperature gradient, spin accumulation, ferromagnetic leads

中图分类号:  (Quantum dots)

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