Predicting charge transport in the presence of polarons: The beyond-quasiparticle regime in SrTiO3
Predicting charge transport in the presence of polarons: The beyond-quasiparticle regime in SrTiO3
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DOI：
10.1103/physrevresearch.1.033138
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发表时间：
2019-05
影响因子：
4.2
通讯作者：
Jin-Jian Zhou;M. Bernardi
中科院分区：
文献类型：
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作者：
Jin-Jian Zhou;M. Bernardi
在具有强电子-声子（$e$-ph）相互作用的材料中，电子在运动过程中携带声子云，形成称为极化子的准粒子。预测极化子体系中的电荷输运及其温度依赖性仍然是一个开放的挑战。在这里，我们提出了第一性原理计算的电荷输运在一个原型材料与大极化子，SrTiO$_{3}$。利用能捕捉到强电子-ph相互作用的累积量重算技术，我们的计算能准确地预测SrTiO $3 $在150$-300 $K之间的电子迁移率实验值。他们进一步揭示，随着温度的升高，电荷输运机制从带状传导转变，其中重整化准粒子的散射占主导地位，到超越准粒子输运机制，该机制由电子与声子云之间的相互作用引起的非相干贡献所支配。我们的工作揭示了SrTiO${3}$中电荷输运的长期探索的微观细节，并为预测具有强$e$-ph相互作用和极化子的材料中的电荷输运提供了一种广泛适用的方法。
In materials with strong electron-phonon ($e$-ph) interactions, the electrons carry a phonon cloud during their motion, forming quasiparticles known as polarons. Predicting charge transport and its temperature dependence in the polaron regime remains an open challenge. Here, we present first-principles calculations of charge transport in a prototypical material with large polarons, SrTiO$_{3}$. Using a cumulant diagram-resummation technique that can capture the strong $e$-ph interactions, our calculations can accurately predict the experimental electron mobility in SrTiO$_{3}$ between 150$-$300 K. They further reveal that for increasing temperature the charge transport mechanism transitions from band-like conduction, in which the scattering of renormalized quasiparticles is dominant, to a beyond-quasiparticle transport regime governed by incoherent contributions due to the interactions between the electrons and their phonon cloud. Our work reveals long-sought microscopic details of charge transport in SrTiO$_{3}$, and provides a broadly applicable method for predicting charge transport in materials with strong $e$-ph interactions and polarons.