摘要：
质子耦合电子转移（PCET）反应因其在生物学中各种能量转换过程中的重要作用而引起广泛关注。作者报告了另一种叫作质子耦合能量转移（PCEnT）的机制，其中质子转移与电子激发能量转移相耦合。
在低温条件下，当PCET受到热力学阻碍时，作者通过实验检测了一系列蒽-酚-吡啶三聚体的激发态行为。理论计算表明，观察到的PCEnT是一个非绝热的单重态-单重态能量转移耦合到质子隧穿，不同于PCET，它发生在施主和受主之间且没有电荷转移。
PCEnT在光激活化学、光子材料和光生物学方面具有潜在的重要意义，但在自然系统中尚未被确定。
Abstract：
Proton-coupled electron transfer (PCET) reactions have generated considerable interest because of their essential role in various energy conversion processes in biology. Pettersson Rimgard et al. report another type of mechanism denoted as proton-coupled energy transfer (PCEnT), in which proton transfer is coupled to electronic excitation energy transfer. PCEnT was experimentally detected when analyzing the excited state behavior for a series of anthracene-phenol-pyridine trimers in low-temperature conditions, where PCET is thermodynamically hindered. Theoretical calculations showed that the observed PCEnT is a non-adiabatic singlet-singlet energy transfer coupled to proton tunneling, which, unlike PCET, occurs with no charge transfer between donor and acceptor. PCEnT is potentially important for light-activated chemistry, photonic materials, and photobiology, but it has yet to be identified for natural systems.
Cavity-mediated electron-photon pairs
腔介导的电子-光子对
作者：ARMIN FEIST, GUANHAO HUANG, GERMAINE AREND, YUJIA YANG, HUGO LOURENÇO-MARTINS, CLAUS ROPERS, etc.
链接：
https://www.science.org/doi/10.1126/science.abo5037
摘要：
电子束与空腔和共振结构的相互作用代表了产生电磁辐射的通用方案。Feist等人在基于光子芯片的微谐振腔中制造了自由电子与真空腔场相匹配的相互作用结构。
当电子通过谐振腔附近时，它们与真空场之间的耦合导致光子在腔内自发产生。由于电子-光子对是相关的，它们应该是自由电子量子光学发展的一个有用的来源，提供增强的成像和传感能力。
Abstract：
The interaction of electron beams with cavities and resonant structures represents a universal scheme for generating electromagnetic radiation. Feist et al. fabricated structures with phase-matched interactions between free electrons and the vacuum cavity field of a photonic chip-based microresonator. As the electrons passed near the resonator, coupling between them and the vacuum field resulted in the spontaneous generation of photons within the cavity. Because the electron-photon pairs are correlated, they should be a useful source for the development of free-electron quantum optics providing enhanced imaging and sensing capabilities.
