Long-range quadrupole electron-phonon interaction from first principles
Long-range quadrupole electron-phonon interaction from first principles
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DOI：
10.1103/physrevb.102.125203
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发表时间：
2020-03
影响因子：
3.7
通讯作者：
Jinsoo Park;Jin-Jian Zhou;V. Jhalani;C. Dreyer;M. Bernardi
中科院分区：
文献类型：
--
作者：
Jinsoo Park;Jin-Jian Zhou;V. Jhalani;C. Dreyer;M. Bernardi
材料中的晶格振动以长程（偶极和四极）和短程（八极和更高）电势的形式诱导电子动力学上的扰动。偶极Frohlich项可以包括在当前的第一性原理电子-声子（$e$-ph）计算中，并且仅存在于极性材料中。四极相互作用在极性和非极性物质中都存在，但目前还不能用第一原理计算。在这里，我们展示了一种方法来计算四极$e$-ph相互作用，并包括它在从头计算的$e$-ph矩阵元素。通过与直接密度泛函微扰理论计算的比较，证明了该方法的准确性。我们将我们的方法应用到硅作为一个非极性半导体的情况下，和四钛酸铅作为一个极性压电材料的情况下，3 $。在这两种材料中，我们发现四极项强烈影响$e$-ph矩阵元素。不同声子模式的$e$-ph相互作用的分析表明，四极项主要影响硅中的光学模式和PbTiO $_3 $中的声学模式，尽管四极项对于所有模式都需要达到定量准确性。电子散射过程和输运的四极$E$-pH相互作用的效果被证明是重要的。我们的方法可以精确的研究$e$-ph相互作用在广泛的非极性，极性和压电材料。
Lattice vibrations in materials induce perturbations on the electron dynamics in the form of long-range (dipole and quadrupole) and short-range (octopole and higher) potentials. The dipole Frohlich term can be included in current first-principles electron-phonon ($e$-ph) calculations and is present only in polar materials. The quadrupole $e$-ph interaction is present in both polar and nonpolar materials, but currently it cannot be computed from first principles. Here we show an approach to compute the quadrupole $e$-ph interaction and include it in ab initio calculations of $e$-ph matrix elements. The accuracy of the approach is demonstrated by comparing with direct density functional perturbation theory calculations. We apply our method to silicon as a case of a nonpolar semiconductor and tetragonal PbTiO$_3$ as a case of a polar piezoelectric material. In both materials we find that the quadrupole term strongly impacts the $e$-ph matrix elements. Analysis of $e$-ph interactions for different phonon modes reveals that the quadrupole term mainly affects optical modes in silicon and acoustic modes in PbTiO$_3$, although the quadrupole term is needed for all modes to achieve quantitative accuracy. The effect of the quadrupole $e$-ph interaction on electron scattering processes and transport is shown to be important. Our approach enables accurate studies of $e$-ph interactions in broad classes of nonpolar, polar and piezoelectric materials.