Phase Transformation and Proximity Coupling in Lateral Heterostructures of Metal Dichalcogenides

二维（2D）材料是原子薄的，原子在层内紧密结合，但层间弱。这种弱层间耦合允许不同材料的垂直堆叠，形成具有有趣性质和应用的异质结构。相反，横向异质结构由不同的二维材料并排放置，具有强键合的一维边界。这种区别类似于一堆不同的盘子（垂直）和摊开在桌子上（横向）。该项目将研究在表面有暴露边界的横向异质结构中出现的新现象。这允许空间分辨探索新的界面物理和异质结构的合理设计与期望的性质。例如，pi先前已经证明他们可以将二维材料从半导体转换为拓扑绝缘体。后者是量子物质的一种状态，它在内部表现为绝缘体，但在表面表现为导体。将拓扑绝缘体与超导体耦合可以产生拓扑超导性，这可以用于量子计算机。该项目还旨在为材料研究领域具有竞争力的劳动力提供培训。学院将通过积极招聘和指导女性和少数族裔学生，努力提高这一劳动力的多样性。以研究为基础的教育材料将与外联活动结合起来，使公众参与进来。二维（2D）材料的快速发展使具有截然不同性质的原子薄层集成到异质结构中，在异质结构中可能出现在单个层中无法获得的奇异行为。大多数二维异质结构的研究都是在垂直几何上进行的，以利用范德华相互作用来创建具有低密度界面电子态的钝化界面。相比之下，横向异质结构独特地允许通常埋在体中的异质界面直接暴露在表面上，从而通过扫描探针技术揭示边界诱导行为。PI旨在探索核壳横向结构赋予相变方案的多功能性，并将邻近研究应用于具有相关电子行为的过渡金属二硫族化合物（TMDCs）。与横向边界相关的局部扰动可以提供调节相互作用的旋钮，从而促进对集体电子态及其在单层体系中的相互作用的理解。本研究还旨在探讨应用横向异质结构在二维拓扑绝缘体边缘诱导拓扑超导的可行性。它揭示了利用二维材料的横向模板对马约拉纳物理的研究，具有在容错量子计算中实现拓扑量子位的潜力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Two-dimensional (2D) materials are atomically thin with atoms strongly bonded within layers but weakly between layers. This weak interlayer coupling allows for the vertical stacking of different materials to form heterostructures with interesting properties and applications. In contrast, a lateral heterostructure consists of different 2D materials placed side by side with one-dimensional boundaries with strong bonding. The difference is akin to a stack of different plates (vertical) vs. being spread out on a table (lateral). This project will investigate novel phenomena that arise in lateral heterostructures with exposed boundaries on the surface. This allows for spatially resolved exploration of new interfacial physics and the rational design of heterostructures with desired properties. For example, the PIs have previously demonstrated that they can convert a 2D material from a semiconductor to a topological insulator. The latter is a state of quantum matter that behaves as an insulator in its interior but as a conductor on its surface. Coupling a topological insulator with a superconductor may give rise to topological superconductivity, which can be used for quantum computers. This project also aims to providing training ground for a competitive workforce in materials research. The PIs will strive to enhance the diversity of this workforce by actively recruiting and mentoring female and minority students. Research-based educational materials are to be integrated with outreach activities to engage the public.The rapid advances in two-dimensional (2D) materials enable the integration of atomically thin layers with vastly different properties into heterostructures, where exotic behaviors that are not accessible in individual layers may emerge. Most studies of 2D heterostructures have been pursued on vertical geometries to take advantages of van der Waals interaction for creating a passivated interface with low density of interfacial electronic states. In contrast, lateral heterostructures uniquely allow for the heterointerfaces, which are typically buried in the bulk, to be directly exposed on surface for unravelling boundary-induced behaviors by scanning probe techniques. The PI aims to explore the versatility of phase transformation scheme empowered by the core-shell lateral architecture and apply the proximity studies to transition metal dichalcogenides (TMDCs) with correlated electronic behaviors. The local perturbations associated with the lateral boundary could provide the knob to tune the interactions and thus facilitate the understanding of collective electronic states as well as their interplay in the monolayer regime. This research also aims to address the feasibility of applying lateral heterostructures to induce topological superconductivity on the edge of 2D topological insulators. It sheds light on the investigation of Majorana physics using lateral templates of 2D materials, holding potential to implement topological qubits in fault-tolerant quantum computation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.