为什么边缘效应对石墨烯纳米谐振器的固有损耗机制很重要？
Why edge effects are important on the intrinsic loss mechanisms of graphene nanoresonators?
摘要：
利用分子动力学模拟研究了不同边缘结构和尺寸的石墨烯纳米谐振器的边缘效应对品质因数的影响。如果施加周期性边界条件，则对于所有类型的石墨烯纳米谐振器都获得非常高的品质因数（$3\times10^{5}$）。然而，如果应用自由边界条件，自由边缘产生的两种效应将大大降低品质因数：虚边振动效应和人为效应。在纳米谐振器的机械振荡过程中，虚边振动将在一对双简并翘曲态之间翻转。翻转过程打破了纳米谐振器机械振荡的相干性，这是极低品质因数的主要机制。如果石墨烯纳米谐振器的机械振荡根据人工振动（系统的非自然振动）被致动，则存在人工效应，这略微降低了品质因数。可以通过根据纳米谐振器的自然振动致动机械振荡来消除人为影响。我们的模拟为最近的实验提供了一个解释，其中测得的品质因数较低，并且在具有自由边缘的相同样本之间变化。
英文摘要：
Molecular dynamics simulations are performed to investigate edge effects on the quality factor of graphene nanoresonators with different edge configurations and of various sizes. If the periodic boundary condition is applied, very high quality factors ($3\times10^{5}$) are obtained for all kinds of graphene nanoresonators. However, if the free boundary condition is applied, quality factors will be greatly reduced by two effects resulting from free edges: the imaginary edge vibration effect and the artificial effect. Imaginary edge vibrations will flip between a pair of doubly degenerate warping states during the mechanical oscillation of nanoresonators. The flipping process breaks the coherence of the mechanical oscillation of the nanoresonator, which is the dominant mechanism for extremely low quality factors. There is an artificial effect if the mechanical oscillation of the graphene nanoresonator is actuated according to an artificial vibration (non-natural vibration of the system), which slightly reduce the quality factor. The artificial effect can be eliminated by actuating the mechanical oscillation according to a natural vibration of the nanoresonator. Our simulations provide an explanation for the recent experiment, where the measured quality factor is low and varies between identical samples with free edges.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
