论文标题
极化光谱函数的绝热理论
Adiabatic theory of the polaron spectral function
论文作者
论文摘要
与声子相连的电子光谱函数的分析理论是在绝热极限中提出的。在化学势大且负$μ\至 - \ infty $的情况下，基态没有绝热变形，并且光谱函数由标准扰动理论定义。在此限制中，我们介绍在电子 - 音波耦合常数中计算出高达第四阶的频谱函数，该函数满足总和到第5矩的标准。在将化学势固定在极化物结合能的情况下，光谱函数由基态以非零绝热变形定义。我们在绝热极限下用有限的极极密度计算光谱函数。我们还展示了如何在绝热限制中评估较高矩的总和规则。与零极性密度的情况相反，有限极性浓度的光谱函数具有一些对极性特征的贡献。
An analytic theory for the spectral function for electrons coupled with phonons is formulated in the adiabatic limit. In the case when the chemical potential is large and negative $μ\to -\infty$ the ground state does not have the adiabatic deformation and the spectral function is defined by the standard perturbation theory. In this limit we present the spectral function calculated up to fourth order in the electron-phonon coupling constant which satisfies the sum rules up to the 5th moment. In the case when the chemical potential is pinned at the polaron binding energy the spectral function is defined by the ground state with a nonzero adiabatic deformation. We calculate the spectral function with the finite polaron density in the adiabatic limit. We also demonstrate how the sum rules for higher moments may be evaluated in the adiabatic limit. Contrary to the case of zero polaron density the spectral function with the finite polaron concentration has some contributions which are characteristic for polarons.
