极化激元泵浦-探测光谱中无序诱导的暗态线形
Disorder-induced Dark States Line Shape in Pump-Probe Spectroscopy of Polaritons
AI总结：
研究极化激元在无序影响下暗态能量处泵浦-探测光谱的线形，通过引入无序使暗态可直接探测，发现包含暗态弛豫和无序会使光谱形状演变，还研究了线形与无序强度关系及渐近标度，有助于分离极化激元响应。
AI中文摘要：
混合光-物质态即极化激元的形成，为塑造分子的光物理和光化学提供了途径，因此对光激发后极化激元的动力学进行了广泛研究，尤其是暗态流形在此过程中的作用仍不清楚。此前已研究过无无序模型中极化激元的泵浦-探测线形，此次研究无序影响下暗态能量处极化激元泵浦-探测光谱的线形。无无序模型中暗态跃迁偶极矩消失无法直接探测，引入无序后其获得小跃迁偶极矩可直接探测。研究表明，包含暗态弛豫和无序会使暗态能量处光谱形状从类似导数形演变为吸收线形，还研究了线形对无序强度的依赖性及其渐近标度。结果表明探测暗态有助于从总信号中分离出极化激元响应。
英文摘要：
The formation of hybrid light--matter states called polaritons provides a route to shape the photophysics and photochemistry of molecules. Accordingly, the dynamics of polaritons following photoexcitation is extensively studied. In particular, the role of the dark state manifold in such processes remains unclear. Here, we investigate the line shape of pump-probe spectra of polaritons emerging at the dark states energy under the influence of disorder. Previously, we already investigated the pump-probe line shapes of polaritons in a disorder-free model and identified distinct signatures of relaxation into dark states, thus providing an indirect probe of this relaxation. Since the transition dipole moment of dark states vanishes in a disorder-free model, they cannot be directly probed. However, dark states acquire small transition dipole moments as soon as disorder is explicitly included in the model enabling them to be directly probed. In this work, we demonstrate that the inclusion of the relaxation to dark states and disorder leads to the evolution of the spectral shape at the DS energy from a derivative-like into an absorptive line shape. Furthermore, we investigate the dependence of the line shape on the disorder strength and its asymptotic scaling for a large number of coupled molecules. Our results demonstrate that probing dark states can help to single out the polaritonic response from the total signal.
