Efficient and robust: Why quantum transport can be close to optimal even in disordered molecular structures

Quantum transport plays an important role in photosynthesis. It is based on a sensitive state that leads to constructive interference, causing waves to overlap and reinforce each other. Preconditions for this state are typically a well-controlled environment and very low temperatures. With the help of theoretical models and complex network analyses, the Freiburg scientists have now succeeded in identifying key geometric properties that enable constructive interference even in disordered media like molecular structures. In particular, dividing the medium into active and inactive components makes the transport efficient as well as robust against thermal fluctuations, i..e., motion of the individual components. Combining these properties as a construction principle would allow scientists to produce molecular structures that achieve optimal efficiency even when control over the precise geometry is suboptimal.

The study is the result of an interdisciplinary project conducted by two junior research groups at FRIAS that merged knowledge of quantum systems and molecular processes with expertise in the analysis of complex networks. The study underlines the necessity of interdisciplinary cooperation for tackling and solving challenging scientific problems.