发表机构
Beijing National Center for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences; School of Physical Sciences, University of Chinese Academy of Sciences; School of Science, Jiangsu University of Science and Technology; School of Physics and Astronomy, Shanghai Jiao Tong University; Institute of High Energy Physics, Chinese Academy of Sciences; Department of Physics, Hubei University; New Cornerstone Science Laboratory; Department of Physics, The University of Hong Kong; Department of Physics, Southern University of Science and Technology（中国科学院北京凝聚态物理国家研究中心与物理研究所; 中国科学院大学物理科学学院; 江苏科技大学理学院; 上海交通大学物理与天文学院; 中国科学院高能物理研究所; 湖北大学物理系; 新基石科学实验室; 香港大学物理系; 南方科技大学物理系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在HfTe5超晶格中实现多隙类螺旋边缘态，通过STM观察和理论建模揭示边缘隙与迷你隙机制，为拓扑器件开关提供平台。
AI 中文摘要
功能性量子自旋霍尔绝缘体（QSHI）受时间反演对称性保护，可抵抗单粒子背散射，在无耗散量子电子学中具有广阔前景。实现具有带隙螺旋边缘态的QSHI，能够实现边缘通道电导的确定性开关，是可编程拓扑电路的关键要求。在此，我们报道了超晶格调制的QSHI HfTe5的实现，其承载涌现的多隙类螺旋边缘态。利用扫描隧道显微镜和谱学，我们在外延单层HfTe5中识别出重构诱导的周期性超晶格调制，并直接观察到边缘通道中的多个类隙特征，伴随态密度中的一系列尖锐峰。结合理论建模，我们将观察到的边缘隙归因于有限宽度耦合，该耦合因超晶格调制而显著增强，而尖锐峰则是自旋轨道耦合的周期性调制在约化布里渊区边界打开迷你隙的表现。值得注意的是，这些尖锐峰在磁场下表现出清晰的塞曼分裂，与拓扑边缘态的螺旋性质一致。我们的结果为在QSHI中工程化带隙螺旋边缘态提供了一条可行途径，并为具有所需开关能力的拓扑器件提供了有前景的平台。
英文摘要
The functional quantum spin Hall insulators (QSHI), protected by time-reversal symmetry against single-particle backscattering, hold great promise for dissipationless quantum electronics. Realization of QSHI with gapped helical edge states, which would enable deterministic on/off switching of the edge-channel conductance, is a key requirement for programmable topological circuits. Here, we report realization of superlattice-modulated QSHI HfTe5 hosting emergent multigap-like helical edge states. Using scanning tunneling microscopy and spectroscopy, we identify a reconstruction-induced periodic superlattice modulation in epitaxial monolayer HfTe5 and directly observe multiple gap-like features in the edge channel, accompanied by a series of sharp peaks in the density of states. Combined with theoretical modelling, we attribute the observed edge gap to the finite-width coupling between the two edges significantly enhanced by the superlattice modulation, whereas the sharp peaks are the manifestations of mini-gaps opening at the reduced Brillouin zone boundaries by the periodic modulation of spin-orbit coupling. Notably, these sharp peaks exhibit clear Zeeman splitting under magnetic fields, consistent with the helical nature of the topological edge states. Our results establish a viable route to engineering gapped helical edge states in QSHI and provide a promising platform for topological devices with desired on/off switchability.
Comments24 pages, 4 figures
Journal refAdvanced Materials, e75159 (2026)
