发表机构
Hong Kong University of Science and Technology; RIKEN Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS); Institute of Physics, Chinese Academy of Sciences; CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences; School of Physics, Beijing Institute of Technology（香港科技大学; 理化学研究所交叉理论与数学科学中心; 中国科学院物理研究所; 中国科学院理论物理研究所理论物理重点实验室; 北京理工大学物理学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究证明基底支撑的双层镍酸盐薄膜可通过层不对称势和层交错拉什巴耦合实现内在拓扑超导相，由镜面对称保护，具有非零缠绕数和马约拉纳边界模式，为拓扑超导提供新平台。
AI 中文摘要
最近在双层镍酸盐中发现的高温超导性凸显了层间耦合的关键作用，并激发了以层间配对为主导的提议。然而，这种配对是否能支持拓扑超导性仍未被探索。在此，我们证明基底支撑的双层镍酸盐薄膜可以承载一种由对角镜面对称性保护的内在时间反演不变拓扑超导相。利用基于第一性原理计算导出的双轨道模型，我们表明适度的层不对称势和层交错拉什巴自旋轨道耦合可在广泛的参数范围内驱动系统进入该拓扑相，并具有主导的层间配对。非平凡拓扑源于自旋分裂成键费米面之一上配对符号的反转，其特征是沿对角方向的非零镜面缠绕数，以及在[11]边缘的马约拉纳克拉默斯对。该相还具有位于对角方向稍远处的体隙节点，具有手性电荷和零能平带。我们讨论了实现和调控该相的实验途径。我们的结果确立了高温双层镍酸盐作为拓扑超导性的有前景平台，其中可调的拓扑转变和马约拉纳边界模式可提供非常规配对的探针。
英文摘要
The recent discovery of high-T$_c$ superconductivity in bilayer nickelates has highlighted the crucial role of interlayer coupling and motivated proposals for dominant interlayer pairing. Whether such pairing can support topological superconductivity, however, remains unexplored. Here, we demonstrate that substrate-supported bilayer nickelate thin films can host an intrinsic time-reversal-invariant topological superconducting phase protected by diagonal mirror symmetry. Using a two-orbital model derived from first-principles calculations, we show that a modest layer-asymmetric potential and layer-staggered Rashba spin-orbit coupling drive the system into this topological phase over a broad parameter range with a dominant interlayer pairing. The nontrivial topology arises from a reversal of the pairing sign on one of the spin-split bonding Fermi surfaces and is characterized by a nonzero mirror winding number along the diagonal direction, as well as a Majorana Kramers pair at the [11] edge. The phase also features bulk gap nodes located slightly away from the diagonal directions, featuring chiral charge and zero-energy flat bands. We discuss experimental routes for realizing and tuning this phase. Our results establish high-T$_c$ bilayer nickelates as a promising platform for topological superconductivity, where tunable topological transitions and Majorana boundary modes can provide probes of unconventional pairing.
Comments8 pages, 4 figures
