中国物理B ›› 2007, Vol. 16 ›› Issue (7): 2075-2081.doi: 10.1088/1009-1963/16/7/045

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

Spin-polarized quantum transport through an Aharonov--Bohm quantum-dot-ring

王建明, 王瑞, 梁九卿   

  1. Department of Physics and Institute of Theoretical Physics, Shanxi University, Taiyuan 030006, China
  • 收稿日期:2007-04-04 修回日期:2007-04-26 出版日期:2007-07-04 发布日期:2007-07-04
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No~10475053).

Spin-polarized quantum transport through an Aharonov--Bohm quantum-dot-ring

Wang Jian-Ming(王建明)†, Wang Rui(王瑞) and Liang Jiu-Qing(梁九卿)   

  1. Department of Physics and Institute of Theoretical Physics, Shanxi University, Taiyuan 030006, China
  • Received:2007-04-04 Revised:2007-04-26 Online:2007-07-04 Published:2007-07-04
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No~10475053).

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摘要： In this paper the quantum transport through an Aharonov--Bohm (AB) quantum-dot-ring with two dot-array arms described by a single-band tight-binding Hamiltonian is investigated in the presence of additional magnetic fields applied to the dot-array arms to produce spin flip of electrons. A far richer interference pattern than that in the charge transport alone is found. Besides the usual AB oscillation the tunable spin polarization of the current by the magnetic flux is a new observation and is seen to be particularly useful in technical applications. The spectrum of transmission probability is modulated by the quantum dot numbers on the up-arc and down-arc of the ring, which, however, does not affect the period of the AB oscillation.

Abstract: In this paper the quantum transport through an Aharonov--Bohm (AB) quantum-dot-ring with two dot-array arms described by a single-band tight-binding Hamiltonian is investigated in the presence of additional magnetic fields applied to the dot-array arms to produce spin flip of electrons. A far richer interference pattern than that in the charge transport alone is found. Besides the usual AB oscillation the tunable spin polarization of the current by the magnetic flux is a new observation and is seen to be particularly useful in technical applications. The spectrum of transmission probability is modulated by the quantum dot numbers on the up-arc and down-arc of the ring, which, however, does not affect the period of the AB oscillation.

Key words: spin-polarized, Aharonov--Bohm ring, interference

中图分类号:  (Quantum dots)

  • 73.63.Kv
72.25.Mk (Spin transport through interfaces) 73.23.-b (Electronic transport in mesoscopic systems)