中国物理B ›› 2014, Vol. 23 ›› Issue (3): 30309-030309.doi: 10.1088/1674-1056/23/3/030309

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All-electrically reading out and initializing topological qubits with quantum dots

陈伟a b, 薛正远b c, 汪子丹b, 沈瑞a   

  1. a National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China;
    b Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China;
    c Laboratory of Quantum Information Technology, and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
  • 收稿日期:2013-10-07 修回日期:2013-12-04 出版日期:2014-03-15 发布日期:2014-03-15
  • 基金资助:
    Project supported by the National Basic Research Program of China (Grant Nos. 2011CB922100, 2011CBA00205, and 2013CB921804), the General Research Fund (GRF) of the Research Grants Council (RGC) of Hong Kong, China (Grant Nos. HKU7058/11P and HKU7045/13P), the Collaborative Research Fund (CRF) of the Research Grants Council (RGC) of Hong Kong, China (Grant No. HKU-8/11G), the University Research Committee (URC) Fund of the Hong Kong University (HKU), China, the National Natural Science Foundation of China (Grant Nos. 11074111, 11023002, and 11004065), the Priority Academic Program Development of Jiangsu Higher Education Institutions, China, the Program for New Century Excellent Talents in University of Ministry of Education of China, the Program for Changjiang Scholars and Innovative Research Team in University, China, and the Fundamental Research Funds for the Central Universities of Ministry of Education of China.

All-electrically reading out and initializing topological qubits with quantum dots

Chen Wei (陈伟)a b, Xue Zheng-Yuan (薛正远)b c, Wang Z. D.(汪子丹)b, Shen Rui (沈瑞)a   

  1. a National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China;
    b Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China;
    c Laboratory of Quantum Information Technology, and School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China
  • Received:2013-10-07 Revised:2013-12-04 Online:2014-03-15 Published:2014-03-15
  • Contact: Wang Z. D., Shen Rui E-mail:zwang@hku.hk;shen@nju.edu.cn
  • Supported by:
    Project supported by the National Basic Research Program of China (Grant Nos. 2011CB922100, 2011CBA00205, and 2013CB921804), the General Research Fund (GRF) of the Research Grants Council (RGC) of Hong Kong, China (Grant Nos. HKU7058/11P and HKU7045/13P), the Collaborative Research Fund (CRF) of the Research Grants Council (RGC) of Hong Kong, China (Grant No. HKU-8/11G), the University Research Committee (URC) Fund of the Hong Kong University (HKU), China, the National Natural Science Foundation of China (Grant Nos. 11074111, 11023002, and 11004065), the Priority Academic Program Development of Jiangsu Higher Education Institutions, China, the Program for New Century Excellent Talents in University of Ministry of Education of China, the Program for Changjiang Scholars and Innovative Research Team in University, China, and the Fundamental Research Funds for the Central Universities of Ministry of Education of China.

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摘要： We analyze the reading and initialization of a topological qubit encoded by Majorana fermions in one-dimensional semiconducting nanowires, weakly coupled to a single level quantum dot (QD). It is shown that when the Majorana fermions are fused by tuning gate voltage, the topological qubit can be read out directly through the occupation of the QD in an energy window. The initialization of the qubit can also be realized via adjusting the gate voltage on the QD, with the total fermion parity conserved. As a result, both reading and initialization processes can be achieved in an all-electrical way.

关键词: quantum dot, Majorana fermion, topological qubit

Abstract: We analyze the reading and initialization of a topological qubit encoded by Majorana fermions in one-dimensional semiconducting nanowires, weakly coupled to a single level quantum dot (QD). It is shown that when the Majorana fermions are fused by tuning gate voltage, the topological qubit can be read out directly through the occupation of the QD in an energy window. The initialization of the qubit can also be realized via adjusting the gate voltage on the QD, with the total fermion parity conserved. As a result, both reading and initialization processes can be achieved in an all-electrical way.

Key words: quantum dot, Majorana fermion, topological qubit

中图分类号:  (Quantum computation architectures and implementations)

  • 03.67.Lx
71.10.Pm (Fermions in reduced dimensions (anyons, composite fermions, Luttinger liquid, etc.)) 74.45.+c (Proximity effects; Andreev reflection; SN and SNS junctions)