Phase Transformation and Proximity Coupling in Lateral Heterostructures of Metal Dichalcogenides

金属二硫化物横向异质结构中的相变和邻近耦合

• 批准号: 2112691
• 负责人: Pengpeng Zhang
• 金额: $ 39.49万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2112691&HistoricalAwards=false
• 关键词: Phase; Transformation; Proximity; Coupling; Lateral

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.

二维(2D)材料是原子薄的，原子在层内强烈结合，但在层之间弱结合。这种弱的层间耦合允许不同材料的垂直堆积形成具有有趣的性质和应用的异质结构。相反，横向异质结构由不同的2D材料组成，它们并排放置，具有一维的边界，具有很强的成键。这种差异类似于一堆不同的盘子(垂直)和铺开在桌子上(横向)。这个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。这使得对新界面物理的空间分辨探索和具有所需性质的异质结构的合理设计成为可能。例如，PI之前已经证明，它们可以将2D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，在其内部充当绝缘体，但在其表面充当导体。将一个拓扑绝缘体与一个超导体耦合可以产生拓扑超导，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基础。专业人员将通过积极招聘和辅导女性和少数族裔学生，努力加强这一劳动力队伍的多样性。以研究为基础的教育材料将与宣传活动相结合，以吸引公众参与。二维(2D)材料的快速发展使具有巨大不同性质的原子薄层集成到异质结构中，其中可能出现在单个层中无法访问的奇异行为。大多数二维异质结的研究都是在垂直几何结构上进行的，以利用范德华相互作用来产生具有低界面电子态密度的钝化界面。相反，横向异质结构独特地允许通常埋藏在块体中的异质界面直接暴露在表面上，以通过扫描探针技术来解开边界感应行为。PI的目的是探索核-壳侧向结构赋予相变方案的通用性，并将邻近研究应用于具有相关电子行为的过渡金属二卤化物(TMDCs)。与横向边界相关的局域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在二维拓扑绝缘体边缘诱导拓扑超导电性的可行性。它揭示了使用2D材料的横向模板对Majorana物理学的研究，具有在容错量子计算中实现拓扑量子比特的潜力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Thermal Hall effect in a van der Waals triangular magnet FeCl2

范德瓦尔斯三角磁体 FeCl2 中的热霍尔效应

• DOI: 10.1103/physrevb.107.l060404
• 发表时间: 2023
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Xu, Chunqiang;Carnahan, Caitlin;Zhang, Heda;Sretenovic, Milos;Zhang, Pengpeng;Xiao, Di;Ke, Xianglin
• 通讯作者: Ke, Xianglin