Mercer Ian P, El-Taha Yasin C, Kajumba Nathaniel, Marangos Jonathan P, Tisch John W G, Gabrielsen Mads, Cogdell Richard J, Springate Emma, Turcu Edmund
School of Physics, Centre for Synthesis and Chemical Biology, University College Dublin, Dublin 4, Ireland.
Phys Rev Lett. 2009 Feb 6;102(5):057402. doi: 10.1103/PhysRevLett.102.057402.
Understanding the role of coherent electronic motion is expected to resolve general questions of importance in macromolecular energy transfer. We demonstrate a novel nonlinear optical method, angle-resolved coherent wave mixing, that separates out coherently coupled electronic transitions and energy transfers in an instantaneous two-dimensional mapping. Angular resolution of the signal is achieved by using millimeter laser beam waists at the sample and by signal relay to the far field; for this we use a high energy, ultrabroadband hollow fiber laser source. We reveal quantum electronic beating with a time-ordered selection of transition energies in a photosynthetic complex.
理解相干电子运动的作用有望解决大分子能量转移中重要的一般性问题。我们展示了一种新颖的非线性光学方法——角分辨相干波混频，它能在一个瞬时二维映射中分离出相干耦合的电子跃迁和能量转移。通过在样品处使用毫米级激光束腰以及将信号中继到远场来实现信号的角分辨率；为此我们使用了一个高能量、超宽带空心光纤激光源。我们在一个光合复合物中通过按时间顺序选择跃迁能量揭示了量子电子拍频。
