Imaging correlations and charge order in transition metal dichalcogenide moiré systems

过渡金属二硫属化物莫尔系统中的成像相关性和电荷顺序

• 批准号: 2103910
• 负责人: Benjamin Feldman
• 金额: $ 45万
• 依托单位: Stanford 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: 2021-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103910&HistoricalAwards=false
• 关键词: Imaging; correlations; charge; order; transition

Non-technical abstract: The electronic properties of materials are governed by the arrangement of atoms and electrons within them. In most cases, this is fixed by the chemistry of the constituent atoms. However, recent advances in the ability to isolate atomically thin crystals and stack them on top of each other provide a route to engineer new synthetic materials. This project investigates how adding a small twist between adjacent layers can be used to control the positions and propagation of electrons. In particular, the rotational misalignment causes the electrons to interact especially strongly with each other, leading to new quantum electronic properties. The research uses a nanoscale sensor to image the resulting electron positions, study the new quantum states that form, and determine the degree to which they can be controlled. The predicted states may have applications in low-power electronics, fault-tolerant quantum computing, and high-density data storage. The project also trains undergraduate and graduate students for careers in quantum technology, fosters the involvement of underrepresented groups in science through summer internships, and inspires the next generation of researchers by developing and implementing outreach activities for high school students and local science festivals.Technical Abstract: Stacking van der Waals materials with similar lattice constants at small relative twist angle can generate exceptionally flat electronic bands that are susceptible to strong Coulomb interactions. This project aims to investigate the plethora of many-body phases that can be realized in twisted devices composed from semiconducting transition metal dichalcogenides (TMDs). The research uses a scanning single-electron transistor (SET) to measure local electronic compressibility and to image charge distribution in moiré TMD systems. The primary goals include: 1) measuring the energy gaps and excitations of correlated electronic ground states; 2) imaging charge ordered phases, such as stripes and generalized Wigner crystals and their melting; and 3) probing the dependence of these emergent states on magnetic field, doping, and twist angle to map out the triangular Hubbard model phase diagram. Moiré TMD systems provide unprecedented flexibility for quantum simulation across a wide swath of Hubbard model parameter space. As a local thermodynamic probe of electronic properties, the SET provides unique insight into this strongly correlated materials platform. In addition, graduate and undergraduate students gain experience in the area of van der Waals assembly and low-temperature scanning probe microscopy.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.

非技术摘要：材料的电子特性受其内部原子和电子的排列控制。在大多数情况下，这是由原子的化学固定的。但是，最近将原子薄晶体分离并彼此堆叠的能力​​的最新进展为设计新的合成材料提供了途径。该项目研究了如何使用相邻层之间的小扭曲来控制电子设备的位置和传播。特别是，旋转未对准使电子彼此之间的相互作用特别强烈，从而导致了新的量子电子特性。该研究使用纳米级传感器对产生的电子位置进行成像，研究形成的新量子状态，并确定可以控制它们的程度。预测的状态可能在低功率电子，容忍故障的量子计算和高密度数据存储中具有应用。该项目还培训本科和研究生从事量子技术的职业，通过暑期实习来培养代表性不足的群体参与科学的参与，并激发下一代研究人员，通过开发和实施高中生的外展活动和实施外展活动，为当地科学节日和当地科学节日。库仑相互作用。该项目旨在研究许多可以在由半导体过渡金属二核苷（TMDS）组成的扭曲器件中实现的多体相。该研究使用扫描单电子晶体管（SET）来测量MoiréTMD系统中的局部电子能力和图像电荷分布。主要目标包括：1）测量相关电子接地态的能量差距和兴奋； 2）成像电荷有序相位，例如条纹和广义的Wigner晶体及其熔化； 3）探测这些新兴状态对磁场，掺杂和扭曲角度的依赖性，以绘制三角形哈伯德模型相图。 MoiréTMD系统为跨哈伯德模型参数空间提供了前所未有的灵活性。作为电子特性的局部热力学探针，该集合为这种强相关的材料平台提供了独特的见解。此外，研究生和本科生在范德华议会和低温扫描探针显微镜方面获得了经验。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响来通过评估来获得的支持。