Photosynthetic reaction center as a quantum heat engine
Photosynthetic reaction center as a quantum heat engine
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DOI：
10.1073/pnas.1212666110
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发表时间：
2013-02-19
影响因子：
11.1
通讯作者：
Scully, Marlan O.
中科院分区：
文献类型：
--
作者：
Dorfman, Konstantin E.;Voronine, Dmitri V.;Scully, Marlan O.
最近在自然和人工光捕获系统中报道了两种归因于量子相干性的看似无关的效应。首先，预测了增强的太阳能电池效率，其次，测量了相干超短激光脉冲序列激发的光合天线中的种群振荡。由于这两个系统都是量子热引擎（QHE），将太阳光子能量转换为有用功（分别为电流或化学能），因此出现了相干性是否也可以提高光合产量的问题。在这里，我们表明，这两种效应产生于相同的人口相干耦合项，这是由噪声引起的，不需要相干光，因此将在自然条件下的太阳能激发的非相干激发。捕光复合物中的电荷分离发生在植物和细菌光合反应中心的一对紧密耦合的叶绿素（特殊的一对）中。我们的特殊对和激光/光电池QHE的能级方案之间的类比，人口振荡和提高产量有一个共同的起源，并预计共存的典型参数。我们预测，在QHE的动机的反应中心的产率提高27%。这表明人造太阳能设备的自然模仿架构。
Two seemingly unrelated effects attributed to quantum coherence have been reported recently in natural and artificial light-harvesting systems. First, an enhanced solar cell efficiency was predicted and second, population oscillations were measured in photosynthetic antennae excited by sequences of coherent ultrashort laser pulses. Because both systems operate as quantum heat engines (QHEs) that convert the solar photon energy to useful work (electric currents or chemical energy, respectively), the question arises whether coherence could also enhance the photosynthetic yield. Here, we show that both effects arise from the same population-coherence coupling term which is induced by noise, does not require coherent light, and will therefore work for incoherent excitation under natural conditions of solar excitation. Charge separation in light-harvesting complexes occurs in a pair of tightly coupled chlorophylls (the special pair) at the heart of photosynthetic reaction centers of both plants and bacteria. We show the analogy between the energy level schemes of the special pair and of the laser/photocell QHEs, and that both population oscillations and enhanced yield have a common origin and are expected to coexist for typical parameters. We predict an enhanced yield of 27% in a QHE motivated by the reaction center. This suggests nature-mimicking architectures for artificial solar energy devices.