Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
J Phys Chem A. 2009 Dec 17;113(50):13825-38. doi: 10.1021/jp9032589.
In this paper, we establish optimal conditions for maximal energy transfer efficiency using solutions for multilevel systems and interpret these analytical solutions with more intuitive kinetic networks resulting from a systematic mapping procedure. The mapping procedure defines an effective hopping rate as the leading order picture and nonlocal kinetic couplings as the quantum correction, hence leading to a rigorous separation of thermal hopping and coherent transfer useful for visualizing pathway connectivity and interference in quantum networks. As a result of these calculations, the dissipative effects of the surrounding environments can be optimized to yield the maximal efficiency, and modulation of the efficiency can be achieved using the cumulative quantum phase along any closed loops. The optimal coupling of the system and its environments is interpreted with the generic mechanisms: (i) balancing localized trapping and delocalized coherence, (ii) reducing the effective detuning via homogeneous line-broadening, (iii) suppressing the destructive interference in nonlinear network configurations, and (iv) controlling phase modulation in closed loop configurations. Though these results are obtained for simple model systems, the physics thus derived provides insights into the working of light harvesting systems, and the approaches thus developed apply to large-scale computation.
在本文中，我们使用多能级系统的解来建立最大能量转移效率的最优条件，并通过系统映射过程得到更直观的动力学网络来解释这些分析解。映射过程将有效跳跃率定义为主阶图像，将非局部动力学耦合定义为量子修正，从而导致热跳跃和相干转移的严格分离，这对于可视化量子网络中的路径连接和干扰非常有用。由于这些计算，周围环境的耗散效应可以得到优化，以获得最大效率，并且可以使用任何闭合回路中的累积量子相位来实现效率的调制。通过通用机制解释系统及其环境的最佳耦合：（i）平衡局域捕获和非局域相干，（ii）通过均匀线宽化减小有效失谐，（iii）抑制非线性网络配置中的相消干涉，（iv）控制闭环配置中的相位调制。尽管这些结果是针对简单的模型系统获得的，但由此得出的物理原理为光捕获系统的工作提供了深入的了解，并且所开发的方法适用于大规模计算。
