Xie Ying-Ming, Lantagne-Hurtubise Étienne, Young Andrea F, Nadj-Perge Stevan, Alicea Jason
Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
Phys Rev Lett. 2023 Oct 6;131(14):146601. doi: 10.1103/PhysRevLett.131.146601.
Recent experiments on Bernal bilayer graphene (BLG) deposited on monolayer WSe_{2} revealed robust, ultraclean superconductivity coexisting with sizable induced spin-orbit coupling. Here, we propose BLG/WSe_{2} as a platform to engineer gate-defined planar topological Josephson junctions, where the normal and superconducting regions descend from a common material. More precisely, we show that if superconductivity in BLG/WSe_{2} is gapped and emerges from a parent state with intervalley coherence, then Majorana zero-energy modes can form in the barrier region upon applying weak in-plane magnetic fields. Our results spotlight a potential pathway for "internally engineered" topological superconductivity that minimizes detrimental disorder and orbital-magnetic-field effects.
近期对沉积在单层二硒化钨（WSe₂）上的伯纳尔双层石墨烯（BLG）进行的实验表明，其存在稳健、超纯净的超导性，并与可观的诱导自旋轨道耦合共存。在此，我们提出将BLG/WSe₂作为一个平台来设计栅极定义的平面拓扑约瑟夫森结，其中正常区域和超导区域源自同一种材料。更确切地说，我们表明，如果BLG/WSe₂中的超导性存在能隙，且源自具有谷间相干性的母体状态，那么在施加弱面内磁场时，马约拉纳零能模会在势垒区域形成。我们的结果突出了一条实现“内部设计”拓扑超导性的潜在途径，该途径可将有害的无序和轨道磁场效应降至最低。
