Nanoscale Polymorph Engineering of Metal-Correlated Insulator Junctions in Monolayer NbSe 2

作者：Yaoyao Chen, Yi-Xin Dai, Yu Zhang, Can Zhang, Lili Zhou, Liangguang Jia, Wei Wang, Xu Han, Huixia Yang, Liwei Liu, Si Chen, Qing‐Feng Sun, Yeliang Wang · 发表于：ACS Nano · 年份：2025 · DOI：10.1021/acsnano.4c17964 · 被引用次数：8 · 研究领域：2D Materials and Applications、Advanced Thermoelectric Materials and Devices、Molecular Junctions and Nanostructures

Lateral junctions composed of quantum many-body materials are highly desirable for realizing physical phenomena and device concepts. However, controllable fabrication of high-quality junctions is challenging, which greatly hinders further exploration. Here, we successfully realize monolayer heterophase homojunctions of metallic H-NbSe 2 and correlated insulating T-NbSe 2 with atomically sharp boundaries via nanoscale polymorph engineering. By applying a scanning tunneling microscopy (STM) tip pulse, T-NbSe 2 can be locally introduced from H-NbSe 2 on the side beneath the tip, thus realizing H/T-NbSe 2 heterophase homojunctions. Our in situ STM measurements, complementary by the theoretical calculations, reveal two types of atomically sharp boundaries with distinct abilities for electron transmission, owing to the structure-dependent boundary coupling effects. Moreover, there are significant electronic interactions among the metallic, correlated insulating, and charge-density-wave states at the H/T-NbSe 2 boundaries. Our results provide insight into the interacting mechanism among diverse quantum many-body states.