Frontiers in the quantum theory of energy transfer

原子间和分子间的能量转移支撑着广泛的生物过程（例如光合作用植物）以及技术设备（例如太阳能电池）。甚至有人认为，植物内部能量转移的高效率依赖于量子效应，但这仍然存在争议。虽然能量转移的基本机制已经被广泛了解了几十年，但最近理论，计算和实验物理学的进展（以及它们之间的综合）导致了可以研究的能量转移过程的范围和复杂性的爆炸。这些包括预测和发现相关现象（例如原子间库仑衰变），用强电场或磁场进行外部控制的新方法，以及从只考虑两个或三个原子或分子到考虑大型合奏的进展。所有这些进步都需要新的理论方法的发展。比如说，一种称为量子电动力学密度泛函理论（QEDFT）的理论可以弥合原子的量子光学图像之间的差距（一个无限小的点状发射体/吸收体）和原子的量子化学图像（原子核周围的电子云）这个项目的总体目标是使用这些技术和其他适当的技术来推动原子之间能量转移效率的界限。和分子，应用于太阳能电池、辐射生物学和激子学（电子学的类似物，但控制分子状态的激发而不是电子的流动）。特别是后者是一个有希望的途径，以低功耗版本的今天的能源密集型计算机。该方法的新奇在于量子光学和量子化学技术的独特组合，这将使我们能够产生以前未考虑过的中间距离能量转移速率和动力学的新结果。该项目还将使用微扰理论的重新表述，以大规模简化少体能量转移速率的分析计算，这将应用于激子器件（如晶体管）的设计和表征。该研究与EPSRC的职权范围的物理科学领域相一致，特别是与光物质相互作用和光学现象。该研究在提高和控制能量传输效率方面的长期应用也可能与太阳能技术领域保持一致。

Interatomic and intermolecular energy transfer underpins a broad range of biological processes (e.g. photosynthesis plants) as well as technological devices (e.g. solar cells). It has even been suggested that the high efficiency of energy transfer within plants relies on quantum effects, but this remains controversial. While the basic mechanism of energy transfer has been known and broadly understood for a number of decades, recently progress in (and synthesis between) theoretical, computational and experimental physics has led to an explosion in the range and complexity of energy transfer-like processes that can be studied. These include the prediction and discovery of related phenomena (e.g. interatomic Coulombic decay), new methods of external control with strong electric or magnetic fields, and a progression from considering only two or three atoms or molecules to considering large ensembles. All of these have advances have required the development of novel theoretical approaches. For example, a theory called quantum electrodynamical density functional theory (QEDFT) can bridge the gap between the quantum-optical picture of an atom (an infinitesimal point-like emitter/absorber) and the quantum chemical picture of an atom (a cloud of electrons around a nucleus).The overall goal of this project is to use these techniques and others as appropriate to push the boundaries of the efficiency of energy transfer between atoms and molecules, with applications in solar cells, radiation biology and excitonics (the analogue of electronics but controlling excitations of molecular states instead of the flow of electrons). The latter in particular is a promising route to low-power versions of today's energy-intensive computers. The novelty of the methodology is a unique mix of techniques from quantum optics and quantum chemistry, which will allow us to generate new results for the rate and dynamics of the rate of energy transfer at the intermediate distances not previously considered. The project will also use reformulations of perturbation theory in order to massively simplify analytical calculation of the rates of few-body energy transfer, which will be applied to design and characterisation of excitonic devices such as transistors. The research aligns with the Physical Sciences area of EPSRC's remit, in particular with light matter interaction and optical phenomena. The longer-term applications of the research in increasing and controlling the efficiency of energy transfer may also align with the solar technology area.