中国物理B ›› 2022, Vol. 31 ›› Issue (1): 17402-017402.doi: 10.1088/1674-1056/ac1572

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Cross correlation mediated by distant Majorana zero modes with no overlap

Lupei Qin(秦陆培), Wei Feng(冯伟), and Xin-Qi Li(李新奇)   

  1. Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
  • 收稿日期:2021-06-04 修回日期:2021-07-12 接受日期:2021-07-18 出版日期:2021-12-03 发布日期:2021-12-28
  • 通讯作者: Xin-Qi Li E-mail:xinqi.li@tju.edu.cn
  • 基金资助:
    This work was supported by the National Key Research and Development Program of China (Grant No. 2017YFA0303304) and the National Natural Science Foundation of China (Grant Nos. 11675016, 11974011, and 61905174).

Cross correlation mediated by distant Majorana zero modes with no overlap

Lupei Qin(秦陆培), Wei Feng(冯伟), and Xin-Qi Li(李新奇)   

  1. Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
  • Received:2021-06-04 Revised:2021-07-12 Accepted:2021-07-18 Online:2021-12-03 Published:2021-12-28
  • Contact: Xin-Qi Li E-mail:xinqi.li@tju.edu.cn
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (Grant No. 2017YFA0303304) and the National Natural Science Foundation of China (Grant Nos. 11675016, 11974011, and 61905174).

摘要: Existing studies via shot noise calculation conclude that the cross correlation between the currents in the two leads connected by a pair of Majorana zero modes (MZMs) vanishes when their coupling energy $∊_{\rm M}\to 0$. Motivated by the intrinsic nature of nonlocality of the MZMs, we revisit this important problem and propose an experimental scheme to demonstrate the nonvanishing cross correlation even at the limit $∊^{}_{\rm M}\to 0$. The proposed scheme employs the Andreev-process-associated branch circuit currents, which are theoretically obtained by applying a decomposition analysis for the total currents while are accessible directly in practical measurement. For different bias voltage setup, we find intriguing results of both negative and positive correlations and carry out simple physical understanding using a quantum jump technique. Importantly, combining together with the evidence of the zero-bias-peak of conductance, the nonlocal cross correlation predicted in this work can help to confirm the existence of the nonlocal MZMs.

关键词: Majorana zero modes, cross correlation, Andreev currents

Abstract: Existing studies via shot noise calculation conclude that the cross correlation between the currents in the two leads connected by a pair of Majorana zero modes (MZMs) vanishes when their coupling energy $∊_{\rm M}\to 0$. Motivated by the intrinsic nature of nonlocality of the MZMs, we revisit this important problem and propose an experimental scheme to demonstrate the nonvanishing cross correlation even at the limit $∊^{}_{\rm M}\to 0$. The proposed scheme employs the Andreev-process-associated branch circuit currents, which are theoretically obtained by applying a decomposition analysis for the total currents while are accessible directly in practical measurement. For different bias voltage setup, we find intriguing results of both negative and positive correlations and carry out simple physical understanding using a quantum jump technique. Importantly, combining together with the evidence of the zero-bias-peak of conductance, the nonlocal cross correlation predicted in this work can help to confirm the existence of the nonlocal MZMs.

Key words: Majorana zero modes, cross correlation, Andreev currents

中图分类号:  (Tunneling phenomena; Josephson effects)

  • 74.50.+r
74.45.+c (Proximity effects; Andreev reflection; SN and SNS junctions) 03.75.Lm (Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations)