• Chinese Physics B
  • Vol. 29, Issue 9, (2020)
Qing Yan1、2, Yan-Feng Zhou3, and Qing-Feng Sun1、2、4、†
Author Affiliations
  • 1International Center for Quantum Materials, School of Physics, Peking University, Beijing 0087, China
  • 2Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
  • 3Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA
  • 4CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
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    DOI: 10.1088/1674-1056/aba272 Cite this Article
    Qing Yan, Yan-Feng Zhou, Qing-Feng Sun. Anomalous Josephson current in quantum anomalous Hall insulator-based superconducting junctions with a domain wall structure[J]. Chinese Physics B, 2020, 29(9): Copy Citation Text show less

    Abstract

    We theoretically study the Josephson effect in a quantum anomalous Hall insulator (QAHI) nanoribbon with a domain wall structure and covered by the superconductor. The anomalous Josephson current, the nonzero supercurrent at the zero superconducting phase difference, appears with the nonzero magnetization and the suitable azimuth angle of the domain wall. Dependent on the configuration of the domain wall, the anomalous current peaks in the Bloch type but disappears in the Néel type because the y-component of magnetization is necessary to break symmetry to arouse the anomalous current. The phase shift of the anomalous current is tunable by the magnetization, the azimuth angle, or the thickness of the domain wall. By introducing a bare QAHI region in the middle of the junction which is not covered by the superconductor, the anomalous Josephson effect is enhanced such that the phase shift can exceed π. Thus, a continuous change between 0 and π junctions is realized via regulating the configuration of the domain wall or the magnetization strength. As long as an s-wave superconductor is placed on the top of the QAHI with a domain wall structure, this proposal can be experimentally fabricated and useful for the phase battery or superconducting quantum bit.
    Qing Yan, Yan-Feng Zhou, Qing-Feng Sun. Anomalous Josephson current in quantum anomalous Hall insulator-based superconducting junctions with a domain wall structure[J]. Chinese Physics B, 2020, 29(9):
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