发表机构
Leibniz Institute for Solid State and Materials Research, IFW Dresden; Würzburg-Dresden Cluster of Excellence ctd.qmat; Institute for Theoretical Physics, Technische Universität Dresden（德累斯顿莱布尼茨固体与材料研究所; 维尔茨堡-德累斯顿卓越集群ctd.qmat; 德累斯顿工业大学理论物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过平板几何简化模型，分析PtBi₂的可调陈超导性，明确了使表面马约拉纳锥产生能隙的两种竞争机制，确定了手性马约拉纳边模的波函数轮廓，绘制出准二维极限下的相图，为相关拓扑超导研究提供了理论支撑。
AI 中文摘要
近期实验表明，PtBi₂是一种外尔半金属，其表面在低温下会成为具有i波能隙对称性的拓扑超导体。该材料体内包含12个外尔锥，而在超导态下，两个表面各额外存在6个马约拉纳锥。我们研究了平板几何下的简化模型，其中有限厚度会使体内外尔锥产生能隙，仅保留表面马约拉纳锥作为低能自由度。我们确定了使这些锥产生能隙的两种竞争机制：锥间杂化会打开平庸能隙，而塞曼场则会打开非平庸能隙。在非平庸区域，手性马约拉纳边模连接着已打开能隙的锥。我们确定了这些边模的波函数轮廓，并将其与锥的动量空间分布关联起来。绘制相图后，我们发现在准二维极限下存在平庸与非平庸两个区域。
英文摘要
Recent experiments indicate that PtBi$_2$ is a Weyl semimetal whose surfaces become topological superconductors with i-wave gap symmetry at low temperature. The bulk hosts 12 Weyl cones while in the superconducting state each of the two surfaces hosts in addition 6 Majorana cones. We study a simplified model in a slab geometry, where the finite thickness gaps out the bulk Weyl cones and leaves the surface Majorana cones as the low-energy degrees of freedom. We identify two competing mechanisms that gap these cones: inter-cone hybridization opens a trivial gap, whereas a Zeeman field opens a nontrivial one. In the nontrivial regime, chiral Majorana edge modes connect the gapped cones. We determine their wavefunction profile and relate it to the momentum-space distribution of the cones. Mapping out the phase diagram, we find both trivial and nontrivial regions in the quasi-two-dimensional limit.
Comments7 pages, 6 figures
