BBSRC-NSF/BIO: Quantum-enhanced long-range energy capture

光合作用为地球上的生命提供动力，为我们提供所有的食物、氧气和大部分的能量。支撑光合作用最初步骤的一般原理已经被进化保存下来；一个被称为天线的蛋白质网络捕获太阳能，并将其传送到一个专门的蛋白质，即反应中心，在那里产生电力。值得注意的是，这些步骤可以以几乎100%的量子效率发生。最近的观察表明，大自然可能通过利用吸收的太阳能从天线到反应中心的波状传输来实现这种高效率。然而，这种量子力学现象在自然系统中的存在和作用备受争议。表征其影响的一个挑战是，对天线的实验是在非本地和孤立的解决方案中进行的。在这个项目中，这是密歇根理工学院（美国）和谢菲尔德大学（英国）的研究人员之间的合作，研究人员将尝试通过研究太阳能如何在本地网络中传输来改变我们的理解。这些实验将同时揭示太阳能有效捕获和转化为电能的机制，并确定增强或抑制潜在量子行为的相互作用。然后，他们将寻求利用这些自然设计原则来构建非本地系统，这些系统具有增强的能力，可以在增加的距离上有效地传播能量。因此，这些研究将为改善生物混合和半导体设备中的能量传输奠定基础，这些设备将应用于与消费电子、太阳能捕获、量子计算、量子通信和光催化剂相关的新兴技术。该项目将同时培养生物学/物理学领域的下一代研究人员，并向公众传播支持自然太阳能转换的迷人基础科学。在光合作用光收集和太阳能转换中，不同物种的蛋白质结构差异很大，但总体设计是保守的；包含光收集复合物（lhc）的网络吸收能量并将能量转移到反应中心（RC）以进行电荷分离。值得注意的是，从吸收到电荷分离可以以几乎100%的量子效率发生。激发态流形内振荡的实验观察导致了一系列理论工作，这些理论工作表明，高效率部分是由于量子相干性。然而，测量到的振荡越来越多地被分配给振动相干，量子相干或其在光收集中的作用的实验证据一直难以捉摸。迄今为止，实验都是在分离的lhc和RCs上进行的，但这些蛋白质在网络中具有天然功能。此外，通过光刻引入的非原生相互作用已被证明可以增强LHC的性能，包括激子-等离子体耦合的能量传输和振子强度。因此，原生网络中的行为以及非原生交互影响这种行为的能力尚未得到研究。在这个项目中，研究人员将使用不同的体外平台来复制天然网络，并为不同的光合蛋白组合引入非天然相互作用。他们将使用先进的光谱学和显微镜来表征激发态特性、能量输运、太阳能转换和网络几何形状。研究结果将为纳米级组织和相互作用如何将能量直接用于光收集和太阳能转换提供蓝图。这个英美合作项目由美国国家科学基金会和英国生物技术和生物科学研究委员会支持。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Photosynthesis powers life on Earth, providing all of our food, oxygen and most of our energy. The general principles underpinning the first steps of photosynthesis have been conserved by evolution; a protein network, termed the antenna, captures solar energy and delivers it to a dedicated protein, the reaction center, where electricity is generated. Remarkably, these steps can occur with almost 100% quantum efficiency. Recent observations suggest that nature may achieve this high efficiency by utilizing wavelike transport of absorbed solar energy from the antenna to the reaction centers. However, the presence and role of such quantum mechanical phenomena in natural systems are highly debated. One challenge to characterizing their impact has been that experiments on the antenna were performed in non-native and isolated solutions. In this project, which is a collaboration between researchers at the Michigan Institute of Technology (US) and the University of Sheffield (UK), the investigators will attempt a step-change in our understanding by investigating how solar energy is transported within the native network. These experiments will simultaneously uncover the mechanisms that give rise to efficient capture and conversion of solar energy to electricity and identify the interactions that enhance or repress the underlying quantum behaviors. They will then seek to exploit these natural design principles to build non-native systems with enhanced abilities to propagate energy efficiently over increased distances. These studies will thereby lay the groundwork for improving energy transport in biohybrid and semi-conductor devices for application to emerging technologies relevant to consumer electronics, solar energy capture, quantum computing, quantum communications and photocatalysts. The project will simultaneously train the next generation of researchers at the biology/physics interface and disseminate the fascinating fundamental science underpinning natural solar energy conversion to the general public.In photosynthetic light harvesting and solar energy conversion, the protein architecture involved varies dramatically with species, yet the general design is conserved; a network containing light-harvesting complexes (LHCs) absorbs and transfers energy to a reaction center (RC) for charge separation. Remarkably, absorption to charge separation can occur with almost 100% quantum efficiency. Experimental observations of oscillations within the excited state manifold led to a body of theoretical work that suggested the high efficiency is, in part, due to quantum coherence. However, the measured oscillations have been increasingly assigned to vibronic coherences, and experimental evidence of quantum coherence or its role in light harvesting has been elusive. To date, experiments have all been performed on isolated LHCs and RCs, yet these proteins function natively within a network. Furthermore, non-native interactions introduced through lithography have been shown to enhance the properties of the LHC, including energy transport and oscillator strength from exciton-plasmon coupling. Thus, the behaviors within the native network as well as the ability of non-native interactions to impact this behavior have not been investigated. In this project, the investigators will use different in vitro platforms to replicate the native network and introduce non-native interactions for different combinations of photosynthetic proteins. They will use advanced spectroscopy and microscopy to characterize excited-state properties, energy transport, solar energy conversion, and network geometry. The results will provide a blueprint for how nanoscale organization and interactions direct energy for light harvesting and solar energy conversion. This collaborative US/UK project is supported by the US National Science Foundation and the UK Biotechnology and Biological Sciences Research Council.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.