AI 中文总结
研究针对单层1T'-WS2因层间耦合难以研究其特性的问题，通过胺插层实现电子解耦，扩大层间距并重构堆叠，可在超导金属和绝缘体间可逆切换，保留非平凡Z2拓扑且诱导手性光学活性，证明分子插层是实现相关物理特性的通用化学途径。
AI 中文摘要
单层1T'-WS2预计是二维拓扑绝缘体，但其本征电子特性被其金属和超导母体相2M-WS2中的强层间耦合掩盖，机械剥离也受此阻碍。本文表明2M-WS2通过简单湿化学反应进行胺插层，生成超晶格，其中1T'层结构保留但被中性分子间隔层电子解耦。插层扩大层间距，重构堆叠，控制插层可在超导金属和绝缘体间可逆切换，密度泛函理论表明解耦层保留单层非平凡Z2拓扑，手性胺插层还诱导手性光学活性。成功插层挑战了长期观点，证明分子插层是实现单层拓扑绝缘体物理和手性范德华超晶格的通用化学途径。
英文摘要
Monolayer 1T'-WS2 is predicted to be a two-dimensional topological insulator, but its intrinsic electronic properties are masked by strong interlayer coupling in its metallic and superconducting bulk parent phase, 2M-WS2. Isolating monolayers by mechanical exfoliation is also hindered by this coupling, preventing experimental examination of monolayer properties. Here we show that 2M-WS2 undergoes amine intercalation through a simple wet-chemical reaction, yielding superlattices in which the 1T' layers are structurally preserved but electronically decoupled by neutral molecular spacers. Intercalation expands the interlayer spacing from 0.5 to 1-4 nm and reconstructs the stacking while preserving the intralayer 1T' framework. Controlled (de)intercalation reversibly switches the system between a superconducting metal and an insulator with an activation gap matching that of the isolated monolayer. Density functional theory indicates that the electronically decoupled layers retain the nontrivial Z2 topology of the monolayer. Chiral amine intercalation further induces chiroptical activity in WS2 electronic transitions. Overall, the successful intercalation challenges the long-held view that group VIB dichalcogenides are inert toward neutral-molecule intercalation and demonstrates molecular intercalation as a general chemical route for realizing monolayer-like topological-insulator physics and enabling chiral van der Waals superlattices in bulk single crystals.
