Xu Bo, Zhang Zejuan, Qin Jiaze, Wu Jiaqi, Wang Luming, Zhu Jiankai, Jiao Chenyin, Zhang Wanli, Xia Juan, Wang Zenghui
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China.
Hubei Key Laboratory of Micro-Nanoelectronic Materials and Devices, Hubei University, Wuhan, 430062, China.
Microsyst Nanoeng. 2025 Jan 22;11(1):18. doi: 10.1038/s41378-024-00827-w.
Nanoelectromechanical systems (NEMS) based on atomically-thin tungsten diselenide (WSe), benefiting from the excellent material properties and the mechanical degree of freedom, offer an ideal platform for studying and exploiting dynamic strain engineering and cross-scale vibration coupling in two-dimensional (2D) crystals. However, such opportunity has remained largely unexplored for WSe NEMS, impeding exploration of exquisite physical processes and realization of novel device functions. Here, we demonstrate dynamic coupling between atomic lattice vibration and nanomechanical resonances in few-layer WSe NEMS. Using a custom-built setup capable of simultaneously detecting Raman and motional signals, we accomplish cross-scale mode coupling between the THz crystal phonon and MHz structural vibration, achieving GHz frequency tuning in the atomic lattice modes with a dynamic gauge factor of 61.9, the best among all 2D crystals reported to date. Our findings show that such 2D NEMS offer great promises for exploring cross-scale physics in atomically-thin semiconductors.
基于原子级薄的二硒化钨（WSe₂）的纳米机电系统（NEMS），受益于其优异的材料特性和机械自由度，为研究和利用二维（2D）晶体中的动态应变工程及跨尺度振动耦合提供了一个理想平台。然而，对于WSe₂ NEMS而言，这样的机会在很大程度上仍未得到探索，这阻碍了对精细物理过程的探究以及新型器件功能的实现。在此，我们展示了少层WSe₂ NEMS中原子晶格振动与纳米机械共振之间的动态耦合。通过使用能够同时检测拉曼信号和运动信号的定制装置，我们实现了太赫兹（THz）晶体声子与兆赫兹（MHz）结构振动之间的跨尺度模式耦合，在原子晶格模式中实现了吉赫兹（GHz）频率调谐，动态应变系数为61.9，这是迄今为止所有已报道的二维晶体中最佳的。我们的研究结果表明，此类二维NEMS在探索原子级薄半导体中的跨尺度物理方面具有巨大潜力。
