Uthailiang Teerapat, Suntijitrungruang Ongart, Issarakul Purin, Pongkitiwanichakul Peera, Boonchui S
Department of Physics, Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand.
Center of Rubber and Polymer Materials in Agriculture and Industry (RPM), Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand.
Sci Rep. 2025 Feb 12;15(1):5220. doi: 10.1038/s41598-025-89474-3.
In natural photosynthesis systems, pigment-protein complexes harvest the photon from sunlight with near-unity quantum efficiency. These complexes show incredible properties that cannot be merely extrapolated from knowledge of their composition. Additionally, the environment perturbing the light-harvesting process significantly affects the mechanism of photosynthesis. This research investigates the photosystem II reaction center (PSII RC) from a new perspective which considers the restricted path of the exciton transfer, in the photosynthesis system, as a quantum trajectory picture with the quantum continuous measurement. In this work, the corridor path of exciton transfer dynamics satisfies the equation of motion, as the spin dynamics, which consists of precession, relaxation, and random force rapidly fluctuating spin splitting arising from the bath. Moreover, the width of the corridor is an important factor for restricting path dynamics resulting in the localization and decoherence phenomenon. Our method is to analyze exciton transfer dynamics through paths on the Bloch sphere, in order to investigate the propagating states in accordance with the weight functional which depends on the coupling parameter between the system and environment as the phonon bath. Our results show that the paths outside the width of the corridor have a considerably lower weight functional and decoherence functional than those inside the width. Therefore, the degrees of localization, the weight functional, and the decoherence functional are related. Furthermore, the simulation reveals three characteristics of exciton transfer: gradual transfer, no transfer, and rapid transfer, relying significantly on the coupling between the system and phonons.
在自然光合作用系统中，色素 - 蛋白质复合物以近乎单位的量子效率捕获来自太阳光的光子。这些复合物展现出令人难以置信的特性，而这些特性不能仅仅从其组成的知识中推断出来。此外，干扰光捕获过程的环境会显著影响光合作用的机制。本研究从一个新的视角研究光系统II反应中心（PSII RC），该视角将光合作用系统中激子转移的受限路径视为具有量子连续测量的量子轨迹图景。在这项工作中，激子转移动力学的走廊路径满足运动方程，如同自旋动力学一样，自旋动力学由进动、弛豫以及由浴产生的快速波动自旋分裂的随机力组成。此外，走廊的宽度是限制路径动力学从而导致局域化和退相干现象的一个重要因素。我们的方法是通过布洛赫球上的路径来分析激子转移动力学，以便根据依赖于作为声子浴的系统与环境之间耦合参数的权重泛函来研究传播状态。我们的结果表明，走廊宽度之外的路径的权重泛函和退相干泛函比宽度之内的路径要低得多。因此，局域化程度、权重泛函和退相干泛函是相关的。此外，模拟揭示了激子转移的三个特征：逐渐转移、不转移和快速转移，这在很大程度上依赖于系统与声子之间的耦合。
