Yong Haiwang, Rouxel Jérémy R, Keefer Daniel, Mukamel Shaul
Department of Chemistry, University of California, Irvine, California 92697, USA.
Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
Phys Rev Lett. 2022 Sep 2;129(10):103001. doi: 10.1103/PhysRevLett.129.103001.
Quantum coherences in electronic motions play a critical role in determining the pathways and outcomes of virtually all photophysical and photochemical molecular processes. However, the direct observation of electronic coherences in the vicinity of conical intersections remains a formidable challenge. We propose a novel time-resolved twisted x-ray diffraction technique that can directly monitor the electronic coherences created as the molecule passes through a conical intersection. We show that the contribution of electronic populations to this signal is canceled out when using twisted x-ray beams that carry a light orbital angular momentum, providing a direct measurement of transient electronic coherences in gas-phase molecules.
电子运动中的量子相干在决定几乎所有光物理和光化学分子过程的路径和结果方面起着关键作用。然而，直接观察锥形交叉点附近的电子相干仍然是一项艰巨的挑战。我们提出了一种新颖的时间分辨扭曲X射线衍射技术，该技术可以直接监测分子通过锥形交叉点时产生的电子相干。我们表明，当使用携带光轨道角动量的扭曲X射线束时，电子布居对该信号的贡献被抵消，从而提供了对气相分子中瞬态电子相干的直接测量。
