标题： 二维铅有机硫属化合物中相干光学声子的缓慢退相 显示英文标题

标题： Slow Dephasing of Coherent Optical Phonons in Two-dimensional Lead Organic Chalcogenides

摘要： 具有强电子-声子相互作用的混合有机-无机半导体通过调控这些相互作用，为开发各种电子、光电子和量子材料提供了一个可编程平台。 然而，在目前的混合半导体（如卤化物钙钛矿）中，具有快速去相位的非谐振动阻碍了对声子进行相干操控的能力。 在这里，我们报告了在铅有机硫属化合物（LOCs）中观察到长寿命的相干声子，LOCs 是一种新型的混合二维半导体家族。 尽管晶格发生畸变，这些材料仍表现出谐波声子动力学，结合了较长的声子去相位时间和可调谐的半导体性质。 在 10K 温度下，观察到长达 75 ps 的去相位时间，并且在散射事件之间最多有 500 次声子振荡周期，对应的无量纲谐波参数比卤化物钙钛矿大一个数量级以上。 声子去相位时间受到非谐性和中心对称性的影响，这两者都可以通过有机配体的设计来调节，因为有机基序和无机基序之间存在直接键合。 本研究为在混合半导体中利用相干声子操控电子性质开辟了新的机会。 显示英文摘要

摘要： Hybrid organic-inorganic semiconductors with strong electron-phonon interactions provide a programmable platform for developing a variety of electronic, optoelectronic, and quantum materials by controlling these interactions. However, in current hybrid semiconductors, such as halide perovskites, anharmonic vibrations with rapid dephasing hinder the ability to coherently manipulate phonons. Here, we report the observation of long-lived coherent phonons in lead organic chalcogenides (LOCs), a new family of hybrid two-dimensional semiconductors. These materials feature harmonic phonon dynamics despite distorted lattices, combining long phonon dephasing times with tunable semiconducting properties. Dephasing time as long as 75 ps at 10 K, with up to 500 cycles of phonon oscillation between scattering events, was observed, corresponding to a dimensionless harmonicity parameter more than an order of magnitude larger than that of halide perovskites. The phonon dephasing time is significantly influenced by anharmonicity and centrosymmetry, both of which can be tuned through the design of the organic ligands thanks to the direct bonding between the organic and inorganic motifs. This research opens new opportunities for the manipulation of electronic properties with coherent phonons in hybrid semiconductors.