Xie Xing, Li Shaofei, Chen Junying, Ding Junnan, He Jun, Liu Zongwen, Wang Jian-Tao, Liu Yanping
Institute of Quantum Physics, School of Physics, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China.
State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Central South University, 932 South Lushan Road, Changsha, Hunan 410083, People's Republic of China.
ACS Appl Mater Interfaces. 2024 Oct 2;16(39):53220-53230. doi: 10.1021/acsami.4c11399. Epub 2024 Sep 19.
Heterostructure engineering provides versatile platforms for exploring exotic physics and enhancing the device performance through interface coupling. Despite the rich array of physical phenomena presented by heterostructures composed of semiconductor and metal van der Waals materials, significant gaps remain in understanding their optical, thermal, and electronic properties. Here, we demonstrate that the valley pseudospin and electron-phonon coupling in monolayer WSe are significantly influenced by interface coupling with 1T-VSe. The heterointerface alters the relaxation process of valley excitons, leading to a transition in magnetic-field-dependent valley polarization from a linear to a "V" shape. Furthermore, we uncover that enhanced electron-phonon coupling exacerbates variations in exciton and valley exciton behavior with temperature, involving higher phonon energies and a shift from acoustic to optical phonons. These findings highlight a promising pathway to manipulate valley excitons and investigate electron-phonon coupling through van der Waals interface interactions.
异质结构工程为探索奇异物理现象和通过界面耦合提高器件性能提供了通用平台。尽管由半导体和金属范德华材料组成的异质结构呈现出丰富的物理现象，但在理解它们的光学、热学和电学性质方面仍存在重大差距。在此，我们证明了单层WSe中的谷赝自旋和电子-声子耦合受到与1T-VSe的界面耦合的显著影响。异质界面改变了谷激子的弛豫过程，导致磁场依赖的谷极化从线性转变为“V”形。此外，我们发现增强的电子-声子耦合加剧了激子和谷激子行为随温度的变化，涉及更高的声子能量以及从声学声子到光学声子的转变。这些发现突出了一条通过范德华界面相互作用来操纵谷激子和研究电子-声子耦合的有前景的途径。
