Molecular Binoculars: How to Spatially Resolve Environmental Fluctuations by Following Two or More Single-Molecule Spectral Trails at a Time

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• 作者：Vassiliy Lubchenko ; Robert J. Silbey
• 刊名：Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：October 24, 2013
• 年：2013
• 卷：117
• 期：42
• 页码：12734-12741
• 全文大小：337K
• 年卷期：v.117,no.42(October 24, 2013)
• ISSN：1520-5207

文摘

We propose a novel type of spectral diffusion experiment that enables one to decouple spatial characteristics of the environmental fluctuations, such as their concentration, from the interaction with the chromophore. Traditional hole broadening experiments do not allow for such decoupling in the common case when the chromophore鈥揺nvironment interaction is scale invariant. Here we propose to simultaneously follow the spectral trails of a small number of nearby chromophores鈥攖wo or more鈥攚hich thereby sense a highly overlapping set of the fluctuations. To this end, we estimate the combined probability distribution for the frequencies of a set of chromophores contained within the same sample. The present setup introduces a new length scale, i.e., the interchromophore distance, which breaks the aforementioned scale invariance and enables one to determine independently the concentration of the environmental fluctuations and their coupling to the chromophores, by monitoring the time after which spectral diffusion of distinct chromophores becomes uncorrelated. We illustrate these results with structural excitations in low temperature glasses.