振动重整化电子能带结构的全非谐非微扰理论
Fully Anharmonic, Non-Perturbative Theory of Vibronically Renormalized Electronic Band Structures
摘要：
我们开发了一个第一性原理的方法，克服了国家的最先进的电子-声子耦合形式主义的主要限制，在固体中的振动相互作用的治疗。特别地，通过从头计算分子动力学模拟，核动力学中的非谐效应被考虑到所有的订单。这种非微扰，自洽的方法评估的响应的波函数沿计算的非谐轨迹，因此，它充分考虑了核和电子之间的耦合自由度。我们通过计算硅和立方钙钛矿SrTiO 3（一种具有软模式的强非谐材料）的温度依赖性，动量分辨光谱函数来验证和证明这一概念的优点。在后一种情况下，我们的方法表明，非谐性和高阶振动耦合在有限温度下对电子结构有很大的贡献，显著影响带隙和有效质量，因此影响宏观性质，如输运系数。
英文摘要：
We develop a first-principles approach for the treatment of vibronic interactions in solids that overcomes the main limitations of state-of-the-art electron-phonon coupling formalisms. In particular, anharmonic effects in the nuclear dynamics are accounted to all orders via ab initio molecular dynamics simulations. This non-perturbative, self-consistent approach evaluates the response of the wave functions along the computed anharmonic trajectory; thus it fully considers the coupling between nuclear and electronic degrees of freedom. We validate and demonstrate the merits of the concept by calculating temperature-dependent, momentum-resolved spectral functions for silicon and the cubic perovskite SrTiO3, a strongly anharmonic material featuring soft modes. In the latter case, our approach reveals that anharmonicity and higher-order vibronic couplings contribute substantially to the electronic-structure at finite-temperatures, noticeably affecting band gaps and effective masses, and hence macroscopic properties such as transport coefficients.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
