arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0808.3256cond-mat.stat-mechcond-mat.mes-hall
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低维系统中的热输运

Heat Transport in low-dimensional systems

Abhishek Dhar

摘要:

介绍了低维系统热传导理论研究的最新成果。这些研究都是在简单但不平凡的模型上进行的。其中大多数是经典系统,但也有一些量子力学的工作。大部分的工作一直在晶格模型对应的声子系统,和一些硬粒子和硬盘系统。最近开发的方法,使用广义朗之万方程和声子格林函数,解释和谐波系统的几个应用。对于相互作用的系统,各种分析方法的基础上的Green-Kubo公式进行了描述,并将其预测与最新的模拟结果进行了比较。这些结果表明,对于动量守恒系统,输运在一维和二维都是反常的,热导率kappa随系统尺寸L的变化而变化,为kappa ~ L^alpha。对于一维相互作用系统,有强有力的数值证据证明普适指数α =1/3,但迄今为止还没有确切的证据。对纳米线和纳米管中的热传导实验也作了简要的讨论。

英文摘要:

Recent results on theoretical studies of heat conduction in low-dimensional systems are presented. These studies are on simple, yet nontrivial, models. Most of these are classical systems, but some quantum-mechanical work is also reported. Much of the work has been on lattice models corresponding to phononic systems, and some on hard particle and hard disc systems. A recently developed approach, using generalized Langevin equations and phonon Green's functions, is explained and several applications to harmonic systems are given. For interacting systems, various analytic approaches based on the Green-Kubo formula are described, and their predictions are compared with the latest results from simulation. These results indicate that for momentum-conserving systems, transport is anomalous in one and two dimensions, and the thermal conductivity kappa, diverges with system size L, as kappa ~ L^alpha. For one dimensional interacting systems there is strong numerical evidence for a universal exponent alpha =1/3, but there is no exact proof for this so far. A brief discussion of some of the experiments on heat conduction in nanowires and nanotubes is also given.

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。

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