Zhou Hao, Liang Kangkai, Bi Liya, Shi Yueqing, Wang Zihao, Li Shaowei
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0309, United States.
Program in Materials Science and Engineering, University of California, San Diego, La Jolla, California 92093-0418, United States.
ACS Appl Electron Mater. 2024 Feb 1;6(3):1530-1541. doi: 10.1021/acsaelm.3c01328. eCollection 2024 Mar 26.
Transition metal dichalcogenide (TMD) moiré superlattices have emerged as a significant area of study in condensed matter physics. Thanks to their superior optical properties, tunable electronic band structure, strong Coulomb interactions, and quenched electron kinetic energy, they offer exciting avenues to explore correlated quantum phenomena, topological properties, and light-matter interactions. In recent years, scanning tunneling microscopy (STM) has made significant impacts on the study of these fields by enabling intrinsic surface visualization and spectroscopic measurements with unprecedented atomic scale detail. Here, we spotlight the key findings and innovative developments in imaging and characterization of TMD heterostructures via STM, from its initial implementation on the in situ grown sample to the latest photocurrent tunneling microscopy. The evolution in sample design, progressing from a conductive to an insulating substrate, has not only expanded our control over TMD moiré superlattices but also promoted an understanding of their structures and strongly correlated properties, such as the structural reconstruction and formation of generalized two-dimensional Wigner crystal states. In addition to highlighting recent advancements, we outline upcoming challenges, suggest the direction of future research, and advocate for the versatile use of STM to further comprehend and manipulate the quantum dynamics in TMD moiré superlattices.
过渡金属二硫属化物（TMD）莫尔超晶格已成为凝聚态物理中一个重要的研究领域。由于其优异的光学性质、可调节的电子能带结构、强库仑相互作用以及淬灭的电子动能，它们为探索关联量子现象、拓扑性质和光与物质相互作用提供了令人兴奋的途径。近年来，扫描隧道显微镜（STM）通过实现具有前所未有的原子尺度细节的本征表面可视化和光谱测量，对这些领域的研究产生了重大影响。在这里，我们重点介绍通过STM对TMD异质结构进行成像和表征的关键发现和创新进展，从其在原位生长样品上的首次应用到最新的光电流隧道显微镜。样品设计从导电衬底发展到绝缘衬底，这不仅扩展了我们对TMD莫尔超晶格的控制，还促进了对其结构和强关联性质的理解，例如结构重构和广义二维维格纳晶体态的形成。除了突出近期的进展外，我们还概述了即将面临的挑战，提出了未来研究的方向，并倡导广泛使用STM来进一步理解和操纵TMD莫尔超晶格中的量子动力学。
