Photosynthetic systems utilize adaptability to respond efficiently to fluctuations in their light environment. As a result, large photosynthetic yields can be achieved in conditions of low light intensity, while photoprotection mechanisms are activated in conditions of elevated light intensity. In sharp contrast with these observations, current theoretical models predict bacterial cell death for physiologically high light intensities. To resolve this discrepancy, we consider a unified framework to describe three stages of photosynthesis in natural conditions, namely light absorption, exciton transfer and charge separation dynamics, to investigate the relationship between the statistical features of thermal light and the Quinol production in bacterial photosynthesis. This approach allows us to identify a mechanism of photoprotection that relies on charge recombination facilitated by the photon bunching statistics characteristic of thermal sunlight. Our results suggest that the flexible design underpinning natural photosynthesis may therefore rely on exploiting the temporal correlations of thermal light, manifested in photo-bunching patterns, which are preserved for excitations reaching the reaction center.

中文翻译：

---

阳光的时间相关性可能有助于细菌光合作用中的光保护

光合作用系统利用适应性来有效地响应其光环境的波动。因此，在低光强度条件下可以实现大的光合产量，而在高光强度条件下会激活光保护机制。与这些观察结果形成鲜明对比的是，当前的理论模型预测了生理高光强度下的细菌细胞死亡。为了解决这种差异，我们考虑了一个统一的框架来描述自然条件下光合作用的三个阶段，即光吸收、激子转移和电荷分离动力学，以研究热光的统计特征与细菌光合作用中醌醇产量之间的关系。这种方法使我们能够确定一种光保护机制，该机制依赖于由热阳光的光子聚集统计特性促进的电荷重组。我们的研究结果表明，支撑自然光合作用的灵活设计可能因此依赖于利用热光的时间相关性，表现在光聚束模式中，这些模式为到达反应中心的激发保留。