量子相干态的二维电子光谱测量的原理、应用和发展

二维电子光谱是一种同时具有高的时间分辨率和光谱分辨率的非线性光谱学方法.它不仅可以对凝聚相分子复杂动力学过程进行直接测量,还可以测量不同电子态、电子态-振动态之间的量子相干过程.2007年,Flemming课题组利用二维电子光谱于低温77 K的条件下在捕光天线蛋白Fenna-Matthews-Olson中发现了能量传递过程存在量子相干现象.尽管后续的实验研究表明,该体系中实验观测到的量子相干现象不可能是由单纯的电子态相干引起的,然而这一实验现象的报道极大地激发了人们对天然或人工模拟光合系统中存在量子相干传能途径的探索,目前还是一个相当活跃的研究领域.本文旨在通过介绍二维电子光谱学原理、装置及其在光合作用体系能量传递中量子相干现象的应用,使二维电子光谱这种实验方法能够在更多的研究领域得以普及与推广.

Quantum coherence measurement with femtosecond time-resolve two-dimensional electronic spectroscopy: principles,applications and outlook

Two-dimensional electronic spectroscopy is a kind of nonlinear optical spectroscopy with both high time resolution and high frequency resolution. It can be used to observe the complex dynamics of a condensed molecular system. Meanwhile it is a very powerful tool to study the coherence between the electronic states or electronic and vibration states. In 2007, Flemming's group reported the long-lived quantum coherence observed in the energy transfer process in the light-harvesting antenna protein complex Fenna-Matthews-Olson at 77 K by means of two-dimensional electronic spectroscopy. Though it has been proved not to arise from the pure electronic coherence later, this discovery has greatly stimulated the exploration of the coherent energy transfer pathways possibly existing in the natural and artificial photosynthetic systems, and this is still a very active area nowadays. Here in this paper we briefly review the principle and set-up of the two-dimensional electronic spectroscopy, and also some of its applications in investigating coherent energy transfer in the photosynthetic and artificial systems, aiming to bring this novel spectroscopic tool into a wider application.