Amarnath R, Bhargavi K S, Kubakaddi S S
Department of Physics, Siddaganga Institute of Technology, Tumakuru 572 103, Karnataka, India.
J Phys Condens Matter. 2020 May 20;32(22):225704. doi: 10.1088/1361-648X/ab720f.
Thermoelectric transport properties, namely, electrical conductivity, electronic thermal conductivity, and diffusion thermopower are theoretically investigated in 3D Dirac semimetal CdAs. We employ Boltzmann transport formalism and consider the electron scattering by charged impurities, short-range disorder, acoustic phonons, and optical phonons. The Boltzmann transport equation is solved using the Ritz iteration technique to obtain the first-order perturbation distribution function for the interaction of electrons with inelastic polar optical phonons scattering. The numerical results are presented in the temperature range 2-300 K with the electron concentration in the range (0.1-10) × 10 cm. It is found that, at low temperature < ~70 K transport coefficients are dominated by charged impurity scattering and at higher temperature the phonon scattering is found to be dominant. The validity of Wiedemann-Franz law is examined. Recently observed experimental results are explained by our theory.
在三维狄拉克半金属CdAs中对热电输运性质，即电导率、电子热导率和扩散热功率进行了理论研究。我们采用玻尔兹曼输运形式，并考虑带电杂质、短程无序、声学声子和光学声子对电子的散射。使用里兹迭代技术求解玻尔兹曼输运方程，以获得电子与非弹性极化光学声子散射相互作用的一阶微扰分布函数。给出了温度范围为2 - 300 K、电子浓度范围为(0.1 - 10)×10 cm时的数值结果。结果发现，在低温< ~70 K时，输运系数由带电杂质散射主导，而在较高温度下，声子散射占主导。检验了维德曼-夫兰兹定律的有效性。我们的理论解释了最近观察到的实验结果。
