Lorentz ratio of a compensated metal
Lorentz ratio of a compensated metal
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DOI：
10.1103/physrevb.98.245134
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发表时间：
2018-12-21
影响因子：
3.7
通讯作者：
Maslov, Dmitrii L.
中科院分区：
文献类型：
--
作者：
Li, Songci;Maslov, Dmitrii L.
金属中违反维德曼-弗朗茨定律的情况可以通过比较洛伦兹比 L =kappa rho/T（其中 kappa 是热导率，rho 是电阻率）与通用索末菲常数 L-0 = (pi(2)/3 )(k(B)/e)(2) 来量化。通过精确求解耦合积分玻尔兹曼方程组，我们获得了以载流子相互作用为主要散射机制的干净补偿金属的洛伦兹比。洛伦兹比在前向散射极限中呈现出一种特殊的简单形式：L/L-0 = (Theta(2))over bar/2，其中 Theta 是散射角。在此限制下，L/L-0 可以任意小。我们还展示了如何在没有精确解的情况下获得相同的结果。我们讨论了如何在我们的模型中解释 II 型 Weyl 半金属 WP2 强烈向下违反 Wiedemann-Franz 定律。
A violation of the Wiedemann-Franz law in a metal can be quantified by comparing the Lorentz ratio, L =kappa rho/T, where kappa is the thermal conductivity and rho is the electrical resistivity, with the universal Sommerfeld constant, L-0 = (pi(2)/3 )(k(B)/e)(2). We obtain the Lorentz ratio of a clean compensated metal with intercarrier interaction as the dominant scattering mechanism by solving exactly the system of coupled integral Boltzmann equations. The Lorentz ratio is shown to assume a particular simple form in the forward-scattering limit: L/L-0 = (Theta(2))over bar/2, where Theta is the scattering angle. In this limit, L/L-0 can be arbitrarily small. We also show how the same result can be obtained without the benefit of an exact solution. We discuss how a strong downward violation of the Wiedemann-Franz law in a type-II Weyl semimetal WP2 can be explained within our model.