Heat current fluctuations and anomalous transport in low-dimensional carbon lattices
Heat current fluctuations and anomalous transport in low-dimensional carbon lattices
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DOI：
10.1103/physrevb.100.241409
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发表时间：
2019-06
影响因子：
3.7
通讯作者：
Ushnish Ray;David T. Limmer
中科院分区：
文献类型：
--
作者：
Ushnish Ray;David T. Limmer
用分子动力学模拟和非平衡重要性抽样方法研究了低维碳晶格的热输运。对于碳纳米管和石墨烯薄片，热输运都是反常的，违反了傅立叶传导定律，系统的热导率依赖于尺寸，并伴随着非线性的温度分布。对于碳纳米管，导热系数随纳米管长度的平方根而增加，而对于石墨烯薄膜，导热系数随碳纳米管长度的对数而增加。碳纳米结构特殊的长度依赖关系和非线性温度分布将碳晶格归入非线性晶格模型的普适类，并表明碳纳米结构中的热输运更好地用Levy走而不是简单的扩散来描述。
Molecular dynamics simulations and nonequilibrium importance sampling are used to study the heat transport of low dimensional carbon lattices. For both carbon nanotubes and graphene sheets heat transport is found to be anomalous, violating Fourier's law of conduction with a system size dependent thermal conductivity and concomitant nonlinear temperature profiles. For carbon nanotubes, the thermal conductivity is found to increase as the square root of the length of the nanotube, while for graphene sheets the thermal conductivity is found to increase as the logarithm of the length of the sheet. The particular length dependence and nonlinear temperature profiles place carbon lattices into a universality class with nonlinear lattice models, and suggest that heat transport through carbon nano-structures is better described by a Levy walk rather than simple diffusion.