中国物理B ›› 2018, Vol. 27 ›› Issue (10): 108503-108503.doi: 10.1088/1674-1056/27/10/108503

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Phase transition and charge transport through a triple dot device beyond the Kondo regime

Yong-Chen Xiong(熊永臣), Zhan-Wu Zhu(朱占武), Ze-Dong He(贺泽东)   

  1. School of Science, and Advanced Functional Material and Photoelectric Technology Research Institution, Hubei University of Automotive Technology, Shiyan 442002, China
  • 收稿日期:2018-06-07 修回日期:2018-07-03 出版日期:2018-10-05 发布日期:2018-10-05
  • 通讯作者: Yong-Chen Xiong E-mail:xiongyc_lx@huat.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11504102), the Scientific Research Items Foundation of Hubei Educational Committee (Grant Nos. Q20161803 and D20171803), the Doctoral Scientific Research Foundation of Hubei University of Automotive Technology (Grant No. BK201407).

Phase transition and charge transport through a triple dot device beyond the Kondo regime

Yong-Chen Xiong(熊永臣), Zhan-Wu Zhu(朱占武), Ze-Dong He(贺泽东)   

  1. School of Science, and Advanced Functional Material and Photoelectric Technology Research Institution, Hubei University of Automotive Technology, Shiyan 442002, China
  • Received:2018-06-07 Revised:2018-07-03 Online:2018-10-05 Published:2018-10-05
  • Contact: Yong-Chen Xiong E-mail:xiongyc_lx@huat.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11504102), the Scientific Research Items Foundation of Hubei Educational Committee (Grant Nos. Q20161803 and D20171803), the Doctoral Scientific Research Foundation of Hubei University of Automotive Technology (Grant No. BK201407).

摘要:

Semiconductor quantum dot structure provides a promising basis for quantum information processing, within which to reveal the quantum phase and charge transport is one of the most important issues. In this paper, by means of the numerical renormalization group technique, we study the quantum phase transition and the charge transport for a parallel triple dot device in the strongly correlated limit, focusing on the effect of inter-dot hopping t beyond the Kondo regime. We find the quantum behaviors depend closely on the initial electron number on the dots, and the present model may map to single, double, and side-coupled impurity models in different parameter spaces. An orbital spin-1/2 Kondo effect between the conduction leads and the bonding orbital, and several magnetic-frustration phases are demonstrated when t is adjusted to different regimes. To understand these phenomena, a canonical transformation of the energy levels is given, and important physical quantities with respect to increasing t and necessary theoretical discussions are shown.

关键词: semiconductor quantum dot device, parallel triple dot structure, quantum phase transition, charge transport, strongly correlated effect

Abstract:

Semiconductor quantum dot structure provides a promising basis for quantum information processing, within which to reveal the quantum phase and charge transport is one of the most important issues. In this paper, by means of the numerical renormalization group technique, we study the quantum phase transition and the charge transport for a parallel triple dot device in the strongly correlated limit, focusing on the effect of inter-dot hopping t beyond the Kondo regime. We find the quantum behaviors depend closely on the initial electron number on the dots, and the present model may map to single, double, and side-coupled impurity models in different parameter spaces. An orbital spin-1/2 Kondo effect between the conduction leads and the bonding orbital, and several magnetic-frustration phases are demonstrated when t is adjusted to different regimes. To understand these phenomena, a canonical transformation of the energy levels is given, and important physical quantities with respect to increasing t and necessary theoretical discussions are shown.

Key words: semiconductor quantum dot device, parallel triple dot structure, quantum phase transition, charge transport, strongly correlated effect

中图分类号:  (Nanoelectronic devices)

  • 85.35.-p
73.63.-b (Electronic transport in nanoscale materials and structures) 71.27.+a (Strongly correlated electron systems; heavy fermions) 73.21.-b (Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems)