AI 中文总结
该研究针对五边形拓扑晶体绝缘体纳米线，通过紧束缚与多轨道计算，揭示其核心及表面的一维狄拉克模式，证实其可作为空间分离螺旋通道的实验实现体系。
AI 中文摘要
我们研究了近期制备的五边形IV-VI族半导体纳米线的电子能带拓扑，该纳米线包含五个在其轴线处交汇的径向{111}孪晶面。紧束缚计算表明，当体带结构发生反转且纳米线中的孪晶面为阳离子型时，其能谱在$\bar{\bar{\text{Γ}}}$附近包含两个空间分离的螺旋狄拉克交叉点：一个定域在核心，另一个定域在外表面；当孪晶面为阴离子型时，对应的能谱保持带隙。这些交叉点源于与孪晶面边缘相关的五个螺旋通道的杂化，奇数个通道会使一个克拉默斯对留在纳米线轴线附近，另一个留在外边界。针对$\text{Pb}_{0.4}\text{Sn}_{0.6}\text{Te}$的实际多轨道计算预测，当纳米线厚度约为50nm及以上时，会形成发育良好的核心模式和表面模式。这些结果证实，五边形SnTe类纳米线是可通过实验实现的、定域在轴向缺陷和外边界的空间分离螺旋通道的实例。
英文摘要
We investigate the electronic band topology of recently fabricated pentagonal IV-VI semiconductor nanowires, which contain five radial $\{111\}$ twin planes meeting at the nanowire axis. Tight-binding calculations show that, when the bulk band structure is inverted and the twin planes in the nanowire are cationic, the spectrum contains two spatially separated helical Dirac crossings near $\overlineΓ$: one localized at the core and the other at the outer surface. When the twin planes are anionic, the corresponding spectra remain gapped. The crossings originate from the hybridization of five helical channels associated with the twin-plane edges, whose odd number leaves one Kramers pair near the nanowire axis and the other at the outer boundary. Realistic multiorbital calculations for $\mathrm{Pb}_{0.4}\mathrm{Sn}_{0.6}\mathrm{Te}$ predict well-developed core and surface modes at nanowire thicknesses of approximately 50~nm and above. These results establish pentagonal SnTe-class nanowires as an experimentally accessible realization of spatially separated helical channels bound to the axial defect and the outer boundary.
Comments25 pages, 18 figures
