高维量子动力学的波包与约化密度方法：在不对称光收集构建块的非线性光谱学中的应用
Wavepacket and Reduced-Density Approaches for High-Dimensional Quantum Dynamics: Application to the Nonlinear Spectroscopy of Asymmetrical Light-Harvesting Building Blocks
AI总结：
本文采用ML-MCTDH波包和HEOM约化密度矩阵方法，结合93维VCH模型，模拟了不对称PPE寡聚物中的激发能转移与弛豫，并探索了其线性及二维非线性光谱特性。
摘要：
本文使用多层多组态含时Hartree（ML-MCTDH）方法的波包和分层运动方程（HEOM）方法的约化密度矩阵，模拟了聚(亚苯基亚乙炔基)（PPE）树枝状聚合物光学激发构建块中的激发能转移（EET）与弛豫。对于在一条支链上含两个环、另一侧含三个环且中间共享一个环的不对称间位取代PPE寡聚物，其前两个激发电子态之间的超快电子漏斗动力学，采用93维从头算振动耦合哈密顿量（VCH）模型（线性或包含双线性与二次项）进行处理。线性VCH模型还用于校准处于计算要求高的非微扰非马尔可夫区域中的开放量子系统。使用ML-MCTDH和HEOM方法模拟了线性响应吸收和发射光谱。后者进一步用于探索趋向二维（2D）光谱学的非线性区域。我们阐明了包含两个主要活性亮态和三阶响应理论中脉冲极限的最小VCH模型，如何以较低成本提供监测早期EET动力学的偏振敏感时间分辨信号。我们还确认了高频乙炔和醌型振动模式所起的关键作用。
英文摘要：
Excitation-energy transfer (EET) and relaxation in an optically excited building block of poly(phenylene ethynylene) (PPE) dendrimers are simulated using wavepackets with the multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method and reduced-density matrices with the hierachical equations of motion (HEOM) approach. The dynamics of the ultrafast electronic funneling between the first two excited electronic states in the asymmetrically meta-substituted PPE oligomer with two rings on one branch and three rings on the other side, with a shared ring in between, is treated with 93-dimensional ab initio vibronic-coupling Hamiltonian (VCH) models, either linear or with bilinear and quadratic terms. The linear VCH model is also used to calibrate an open quantum system that falls in a computationally demanding non-perturbative non-Markovian regime. The linear-response absorption and emission spectra are simulated with both the ML-MCTDH and HEOM methods. The latter is further used to explore the nonlinear regime towards two-dimensional (2D) spectroscopy. We illustrate how a minimal VCH model with the two main active bright states and the impulsive-pulse limit in third-order response theory may provide at lower cost polarization-sensitive time-resolved signals that monitor the early EET dynamics. We also confirm the essential role played by the high-frequency acetylenic and quinoidal vibrational modes.
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。
