论文标题
石墨烯和石墨烯纳米纤维的混沌动力学
Chaotic dynamics of graphene and graphene nanoribbons
论文作者
论文摘要
我们研究石墨烯结构的混沌动力学，考虑到各种宽度的周期性，无缺陷，石墨烯片和石墨烯纳米纤维（GNR）。通过数值计算最大Lyapunov指数，我们量化了两个系统中一系列能量的混沌性。我们发现，在所有情况下，混乱的强度随着能量密度的增加而增加，并且石墨烯中混乱的发作很慢，在系统的自然振荡超过10^4 $之后变得很明显。对于GNR，我们还研究了宽度和手性（扶手椅或曲折边缘）对它们混乱行为的影响。我们的结果表明，由于自由边缘，GNR的混沌性比周期性石墨烯片强，并且通过增加宽度而降低，渐近地趋于散装值。另外，扶手椅GNR的混沌强度高于相同宽度的锯齿形丝带。此外，我们表明$ {}^{12} c $和$ {}^{13} c $碳同位素的组成对其混乱强度有很小的影响。
We study the chaotic dynamics of graphene structures, considering both a periodic, defect free, graphene sheet and graphene nanoribbons (GNRs) of various widths. By numerically calculating the maximum Lyapunov exponent, we quantify the chaoticity for a spectrum of energies in both systems. We find that for all cases, the chaotic strength increases with the energy density, and that the onset of chaos in graphene is slow, becoming evident after more than $10^4$ natural oscillations of the system. For the GNRs, we also investigate the impact of the width and chirality (armchair or zigzag edges) on their chaotic behavior. Our results suggest that due to the free edges the chaoticity of GNRs is stronger than the periodic graphene sheet, and decreases by increasing width, tending asymptotically to the bulk value. In addition, the chaotic strength of armchair GNRs is higher than a zigzag ribbon of the same width. Further, we show that the composition of ${}^{12}C$ and ${}^{13}C$ carbon isotopes in graphene has a minor impact on its chaotic strength.
