Ab initio electron-two-phonon scattering in GaAs from next-to-leading order perturbation theory
Ab initio electron-two-phonon scattering in GaAs from next-to-leading order perturbation theory
复制标题
DOI：
10.1038/s41467-020-15339-0
复制
发表时间：
2020-03-30
影响因子：
16.6
通讯作者：
Bernardi, Marco
中科院分区：
文献类型：
--
作者：
Lee, Nien-En;Zhou, Jin-Jian;Bernardi, Marco
电子-声子（e-ph）相互作用通常在微扰论的最低阶处理。在这里，我们推导出次主导阶e-ph相互作用，并从第一性原理计算相关的电子-双声子（2 ph）散射率。推导涉及两圈费曼图的松原和，数值计算是具有挑战性的，因为它们涉及两个晶体动量的布里渊区积分，并严重依赖于中间态寿命。使用Monte Carlo积分与自洽更新的中间态寿命，我们计算和收敛的2 ph散射率，并分析其能量和温度依赖性。我们将我们的方法应用到GaAs，一种弱极性半导体与占主导地位的光学模式远程e-ph相互作用。我们发现，2 ph散射率是大的近一半的值的一个声子率，包括2 ph过程是必要的，以准确地预测电子迁移率在GaAs中的第一原理。
Electron-phonon (e-ph) interactions are usually treated in the lowest order of perturbation theory. Here we derive next-to-leading order e-ph interactions, and compute from first principles the associated electron-two-phonon (2ph) scattering rates. The derivations involve Matsubara sums of two-loop Feynman diagrams, and the numerical calculations are challenging as they involve Brillouin zone integrals over two crystal momenta and depend critically on the intermediate state lifetimes. Using Monte Carlo integration together with a self-consistent update of the intermediate state lifetimes, we compute and converge the 2ph scattering rates, and analyze their energy and temperature dependence. We apply our method to GaAs, a weakly polar semiconductor with dominant optical-mode long-range e-ph interactions. We find that the 2ph scattering rates are as large as nearly half the value of the one-phonon rates, and that including the 2ph processes is necessary to accurately predict the electron mobility in GaAs from first principles.