Coherent Energy Transfer under Incoherent Light Conditions
Coherent Energy Transfer under Incoherent Light Conditions
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DOI：
10.1021/jz3010317
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发表时间：
2012-11-01
影响因子：
5.7
通讯作者：
Scholes, Gregory D.
中科院分区：
文献类型：
--
作者：
Fassioli, Francesca;Olaya-Castro, Alexandra;Scholes, Gregory D.
最近的二维电子光谱（2DES）实验报道了在几个光捕获天线的电子激发的相干动力学的证据。然而，2DES使用超快相干激光脉冲作为激发源;因此，目前存在关于在自然阳光-非相干-照明条件下是否存在相干激发动力学的争论。在这封信中，我们表明，即使非相干光激发的电子态，没有初始量子叠加激子状态，能量转移可以进行量子相干，如果声子环境的非平衡动力学发生。这种非平衡行为表现在电子激发的非马尔可夫演化中，是许多光合系统的典型特征。因此，我们认为，捕光天线的机制，可以支持相干进化下的非相干照明。
Recent two-dimensional electronic spectroscopy (2DES) experiments have reported evidence of coherent dynamics of electronic excitations in several light-harvesting antennae. However, 2DES uses ultrafast coherent laser pulses as an excitation source; therefore, there is a current debate on whether coherent excitation dynamics is present under natural sunlight - incoherent - illumination conditions. In this letter, we show that even if incoherent light excites an electronic state with no initial quantum superpositions among excitonic states, energy transfer can proceed quantum coherently if nonequilibrium dynamics of the phonon environment takes place. Such nonequilibrium behavior manifests itself in non-Markovian evolution of electronic excitations and is typical of many photosynthetic systems. We therefore argue that light-harvesting antennae have mechanisms that could support coherent evolution under incoherent illumination.