The creation and movement of dislocations determine the nonlinear mechanics of materials. At the nanoscale, the number of dislocations in structures become countable, and even single defects impact material properties. While the impact of solitons on electronic properties is well studied, the impact of solitons on mechanics is less understood. In this study, we construct nanoelectromechanical drumhead resonators from Bernal stacked bilayer graphene and observe stochastic jumps in frequency. Similar frequency jumps occur in few-layer but not twisted bilayer or monolayer graphene. Using atomistic simulations, we show that the measured shifts are a result of changes in stress due to the creation and annihilation of individual solitons. We develop a simple model relating the magnitude of the stress induced by soliton dynamics across length scales, ranging from <0.01 N/m for the measured 5 μm diameter to ∼1.2 N/m for the 38.7 nm simulations. These results demonstrate the sensitivity of 2D resonators are sufficient to probe the nonlinear mechanics of single dislocations in an atomic membrane and provide a model to understand the interfacial mechanics of different kinds of van der Waals structures under stress, which is important to many emerging applications such as engineering quantum states through electromechanical manipulation and mechanical devices like highly tunable nanoelectromechanical systems, stretchable electronics, and origami nanomachines.

中文翻译：

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由于二维范德华界面中的孤子动力学，随机应力跳跃。

位错的产生和运动决定了材料的非线性力学。在纳米级，结构中的位错数量变得可数，甚至单个缺陷也会影响材料性能。尽管对孤子对电子性能的影响进行了充分的研究，但对孤子对力学的影响却鲜为人知。在这项研究中，我们从Bernal叠层双层石墨烯构建了纳米机电鼓头谐振器，并观察了频率的随机跳跃。类似的跳频发生在几层但不扭曲的双层或单层石墨烯中。使用原子模拟，我们显示测得的位移是由于单个孤子的产生和an灭而引起的应力变化的结果。我们建立了一个简单的模型，该模型将跨长度尺度的孤子动力学引起的应力的大小关联起来，测量的5μm直径的<0.01 N / m至38.7 nm模拟的〜1.2 N / m。这些结果表明，二维共振器的灵敏度足以探测原子膜中单位错的非线性力学，并提供了一个模型来理解应力下不同范德华结构的界面力学，这对于许多新兴应用非常重要，例如通过机电操纵和机械设备（如高度可调的纳米机电系统，可伸缩电子设备和折纸纳米机器）来实现工程量子态。