Real-space visualization of a defect-mediated charge density wave transition

• 成果类型: Article
• 署名作者: Hart, James L.; Pan, Haining; Siddique, Saif; Schnitzer, Noah; Mallayya, Krishnanand; Xu, Shiyu; Kourkoutis, Lena F.; Kim, Eun-ah; Cha, Judy J.
• 署名单位: Cornell University; Cornell University; Cornell University; Cornell University; Ewha Womans University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8833
• DOI: 10.1073/pnas.2402129121
• 发表日期: 2024-08-13
• 关键词: stacking; superconductivity; microscopy; 1t-tas2

摘要

We study the coupled charge density wave (CDW) and insulator-to-metal transitions in the 2D quantum material 1T-TaS2. By applying in situ cryogenic 4D scanning transmission electron microscopy with in situ electrical resistance measurements, we directly visualize the CDW transition and establish that the transition is mediated by basal dislocations (stacking solitons). We find that dislocations can both nucleate and pin the transition and locally alter the transition temperature T-c by nearly similar to 75 K. This finding was enabled by the application of unsupervised machine learning to cluster five-dimensional, terabyte scale datasets, which demonstrate a one-to-one correlation between resistance-a global property-and local CDW domain-dislocation dynamics, thereby linking the material microstructure to device properties. This work represents a major step toward defect-engineering of quantum materials, which will become increasingly important as we aim to utilize such materials in real devices.