Institute for Quantum Science and Engineering, Texas A&M University, College Station, Texas 77843, USA.
Max Planck Institute for the Physics of Complex Systems, D-01187 Dresden, Germany.
Phys Rev E. 2017 Jun;95(6-1):062109. doi: 10.1103/PhysRevE.95.062109. Epub 2017 Jun 8.
Photosynthesis is the basic process used by plants to convert light energy in reaction centers into chemical energy. The high efficiency of this process is not yet understood today. Using the formalism for the description of open quantum systems by means of a non-Hermitian Hamilton operator, we consider initially the interplay of gain (acceptor) and loss (donor). Near singular points it causes fluctuations of the cross section which appear without any excitation of internal degrees of freedom of the system. This process occurs therefore very quickly and with high efficiency. We then consider the excitation of resonance states of the system by means of these fluctuations. This second step of the whole process takes place much slower than the first one, because it involves the excitation of internal degrees of freedom of the system. The two-step process as a whole is highly efficient, and the decay is biexponential. We provide, if possible, the results of analytical studies, otherwise characteristic numerical results. The similarities of the obtained results to light harvesting in photosynthetic organisms are discussed.
光合作用是植物将光能在反应中心转化为化学能的基本过程。这个过程的高效率至今尚未被理解。使用非厄米哈密顿算符来描述开放量子系统的形式主义，我们首先考虑增益（受体）和损耗（供体）的相互作用。在近奇异点处，它会导致截面的波动，而这些波动的出现不需要系统内部自由度的任何激发。因此，这个过程发生得非常快，效率也很高。然后，我们考虑通过这些波动来激发系统的共振态。整个过程的第二步比第一步慢得多，因为它涉及到系统内部自由度的激发。整个两步过程的效率非常高，衰减是双指数的。如果可能的话，我们会提供分析研究的结果，否则会给出典型的数值结果。讨论了所得到的结果与光合作用生物中光捕获的相似性。
