论文标题
光学线形的随机激子散散散射理论：重新归一化的多体贡献
Stochastic exciton-scattering theory of optical lineshapes: Renormalized many-body contributions
论文作者
论文摘要
光谱线形为凝结阶段的量子转变提供了一个框架的窗口。在本文中，我们建立在一个随机模型的基础上，以说明宽带脉冲激光刺激产生的非平稳背景过程。特别是，我们考虑了在平均场近似中的完整骨气多体汉密尔顿（Hamiltonian）产生的成对透明作用的贡献，将耦合与系统的耦合视为随机噪声项。使用IT {phiss}转换，我们考虑了模型的两个限制案例，这些情况导致观察到的光谱波动与环境的光谱密度之间的联系。在第一种情况下，我们考虑了一个布朗的环境，并表明这会产生光谱动力学，从而放松以形成装扮的激子状态并恢复一种像光谱相关性的安德森 - 库博一样的形式。在第二种情况下，我们假设频谱是Anderson-Kubo喜欢的，并反转以确定相应的背景。使用Jensen不等式，我们获得了背景光谱密度的上限。此处介绍的结果提供了将随机模型应用于广泛问题的技术工具。
Spectral line-shapes provide a window into the local environment coupled to a quantum transition in the condensed phase. In this paper, we build upon a stochastic model to account for non-stationary background processes produced by broad-band pulsed laser stimulation. In particular, we consider the contribution of pair-fluctuations arising from the full bosonic many-body Hamiltonian within a mean-field approximation, treating the coupling to the system as a stochastic noise term. Using the It{ô} transformation, we consider two limiting cases for our model which lead to a connection between the observed spectral fluctuations and the spectral density of the environment. In the first case, we consider a Brownian environment and show that this produces spectral dynamics that relax to form dressed excitonic states and recover an Anderson-Kubo-like form for the spectral correlations. In the second case, we assume that the spectrum is Anderson-Kubo like, and invert to determine the corresponding background. Using the Jensen inequality, we obtain an upper limit for the spectral density for the background. The results presented here provide the technical tools for applying the stochastic model to a broad range of problems.
