Precise control of energy transfer between single dipole-coupled molecules in a tunable half-wavelength Fabry-Pérot resonator at cryogenic temperatures

在低温下可调谐半波长法布里-珀罗谐振器中单个偶极耦合分子之间能量传输的精确控制

• 批准号: 196392417
• 负责人: Professor Dr. Alfred J. Meixner
• 金额: --
• 依托单位: Institut für Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/196392417?language=en
• 关键词: Precise; control; energy; transfer; between

The Förster resonance energy transfer is an intensively discussed and often applied photo-physical process. Its mechanism bases on dipole-dipole interaction, whereby the energy absorbed by a donor-molecule is transferred to an acceptor-molecule. Since several years, there is a controversial debate about how this or similar energy transfer processes can be controlled actively. Active control means that the dynamics of the transfer in time time and energy domain are to be altered by a controllable environment leading either to an enhancement or complete suppression of the transfer. This issue is especially of great importance for the design of micro- or nanoscopic photonic switches or for photovoltaic devices. As an example, the extremely high energy conversion efficiency of photosynthetic complexes grounds on sophisticated energy transfer pathways, which finally leads to the generation of electrons or the splitting of water.During the previous proposal period we started to analyze and control the Förster-Transfer between two chromophores by an accurately controllable photonic environment, which was realized by a tunable lambda/2-Fabry-Pérot-resonator. In contrast to plasmonic structures, which allow to enhance of the photonic density of states in close proximity, the photonic impact on quantum systems can be monitored and manipulated in a very precise and reproducible manner by our tunable microresonators. By means of spectral and time resolved measurements on FRET-coupled systems in our resonators we were able to study and theoretically model the energy transfer dynamics. Also, we were able to determine the energy transfer rate constant of single FRET-pairs for various mirror separations. Thus, we could find out that the FRET-rate constant is not altered by our resonators in contrast to the transfer efficiency. The goal of the following proposal is to investigate dipole-coupled energy transfer between pairs of donor-acceptor molecules from the low coupling regime to strong coupling in a tunable half wavelength Fabry-Pérot resonator. In order to gain high quality data which are not hampered by inhomogeneous broadening, overlapping vibronic bands or conformational changes, the experiments will be performed at the single-molecule level with isolated donor-acceptor pairs at cryogenic temperatures. First, we will develop a tunable resonator which allows us to control the photonic environment at liquid helium temperatures. Then, single quantum systems and dipole-dipole coupled model systems shall be examined by spectrally and time resolved microscopy. For studying the coupling dynamics of such systems we are planning to perform pump-probe measurements with pulsed excitation on single systems for various mirror separations. Data analysis is based on theoretical models and simulations.

Förster共振能量转移是一个被广泛讨论和经常应用的光物理过程。其机理基于偶极-偶极相互作用，由此由供体分子吸收的能量被转移到受体分子。多年来，关于如何主动控制这种或类似的能量转移过程存在争议。主动控制意味着在时间和能量域中的转移的动态将被可控环境改变，从而导致转移的增强或完全抑制。这一问题对于微米或纳米级光子开关或光伏器件的设计尤其重要。例如，光合复合物的极高能量转换效率基于复杂的能量传递途径，最终导致电子的产生或水的分裂。在之前的提案期间，我们开始通过精确可控的光子环境来分析和控制两个发色团之间的Förster转移，这是通过可调谐λ/2-Fabry-Pérot谐振器实现的。与等离子体结构相比，它允许增强近距离的光子态密度，光子对量子系统的影响可以通过我们的可调谐微谐振器以非常精确和可再现的方式进行监测和操纵。通过对共振器中FRET耦合系统的光谱和时间分辨测量，我们能够研究和理论建模能量传递动力学。此外，我们能够确定的能量转移速率常数的单个FRET对各种镜分离。因此，我们可以发现，与传输效率相比，FRET速率常数不被我们的谐振器改变。下面的建议的目标是研究偶极耦合的能量转移之间的供体-受体分子对从低耦合制度强耦合在一个可调谐的半波长法布里-珀罗谐振腔。为了获得不受不均匀加宽、重叠电子振动带或构象变化阻碍的高质量数据，实验将在低温下用孤立的供体-受体对在单分子水平上进行。首先，我们将开发一个可调谐振器，使我们能够控制在液氦温度下的光子环境。然后，单量子系统和偶极-偶极耦合模型系统将通过光谱和时间分辨显微镜进行检查。为了研究这种系统的耦合动力学，我们计划在单个系统上进行脉冲激发的泵浦-探测测量，用于各种镜分离。数据分析基于理论模型和模拟。