相控马约拉纳零模在交错磁拓扑绝缘体约瑟夫森结中

中文摘要 AI 辅助

我们利用依赖于晶面的安德烈夫相移，通过相位偏置在三维交错磁拓扑绝缘体约瑟夫森结中控制拓扑超导性。在两个传统s波超导体之间的弱连接区域，d波交错磁序导致表面狄拉克锥的动量发生依赖于晶面的偏移。参与安德烈夫反射的态所产生的净动量带来了额外的传播相位，这些相位在不同晶面间存在差异。因此，分辨晶面的安德烈夫谱在不同相位偏置处表现出能隙闭合，从而产生承载马约拉纳零模（MZMs）的拓扑超导区域。我们进一步表明，调节相位偏置可以控制这些模式的空间局域化。相关的拓扑超导转变仅受化学势适度变化的影响较弱，从而无需精细调节至狄拉克点。我们的结果建立了一个平台，通过调节交错磁拓扑绝缘体约瑟夫森结中的超导相位偏置来实现和空间控制MZMs。

英文摘要

We exploit facet-dependent Andreev phase shifts to control topological superconductivity with a phase bias in a three-dimensional altermagnetic topological-insulator Josephson junction. In the weak link between two conventional $s$-wave superconductors, the $d$-wave altermagnetic order produces anisotropic momentum shifts of the surface Dirac cones. The resulting net momentum of the states involved in Andreev reflection generates additional propagation phases that differ between facets. Consequently, the facet-resolved Andreev spectra exhibit gap closings at distinct phase biases, giving rise to topological superconducting regimes that host Majorana zero modes (MZMs). We further show that the spatial locations of the MZMs can be controlled by the phase bias. Moreover, these topological superconducting transitions are only weakly affected by moderate variations in the chemical potential, obviating the need for fine-tuning to the Dirac point. Our results establish a platform for realizing and spatially controlling MZMs by tuning the superconducting phase bias in altermagnetic topological-insulator Josephson junctions.

发表机构

• Huazhong University of Science and Technology（华中科技大学）
• Tsung-Dao Lee Institute（李政道研究所）
• School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院）
• High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences（中国科学院合肥物质科学研究院高磁场实验室）
• College of Physics and Optoelectronic Engineering, Department of Physics, Jinan University（暨南大学物理与光电工程学院）
• Hefei National Laboratory（合肥国家实验室）
• Shanghai Research Center for Quantum Sciences（上海量子科学研究中心）

机构由 AI 辅助整理，请以论文原文为准。

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11 pages, 4 figures