Heat transport in nonlinear lattices free from the umklapp process
Heat transport in nonlinear lattices free from the umklapp process
复制标题
不受 umklapp 过程影响的非线性晶格中的热传输
DOI：
10.1103/physreve.105.024140
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发表时间：
2022
影响因子：
2.4
通讯作者：
Kitamura Tomoya
中科院分区：
文献类型：
--
作者：
Yoshimura Kazuyuki;Doi Yusuke;Kitamura Tomoya
我们构造了一维非线性格，它具有umklapp过程不存在，而在势函数中只包含正规过程的特殊性质。这些晶格具有长程四次非线性和最近邻谐波相互作用，有或没有谐波现场电位。采用非平衡分子动力学模拟方法，研究了有和无谐波场势的两种晶格的热输运情况。结果表明，两种情况下均存在弹道热输运，即热导率与晶格尺寸之间存在标度关系。这一结果直接验证了佩尔斯的假设，即只有umklapp过程才会产生热阻，而普通过程则不会。
We construct one-dimensional nonlinear lattices having the special property such that the umklapp process vanishes and only the normal processes are included in the potential functions. These lattices have long-range quartic nonlinear and nearest-neighbor harmonic interactions with/without harmonic onsite potential. We study heat transport in two cases of the lattices with and without harmonic onsite potential by nonequilibrium molecular dynamics simulation. It is shown that the ballistic heat transport occurs in both cases, i.e., the scaling lawholds between the thermal conductivityand the lattice size. This result directly validates Peierls's hypothesis that only the umklapp processes can cause the thermal resistance while the normal ones do not.