DNA scaffold supports long-lived vibronic coherence in an indodicarbocyanine (Cy5) dimer
Sara H. Sohail, John P. Otto, Paul D. Cunningham, Young C. Kim, Ryan E. Wood, Marco A. Allodi, Jacob S. Higgins, Joseph S. Melinger, Gregory S. Engel
Abstract
for the 1-bp dimer, are coherences between vibronic exciton states and that these coherences persist for ∼300 fs. Our observations are well described by a vibronic exciton model, which predicts the excitonic coupling strength in the dimers and the resulting molecular exciton states. The energy spacing between those states closely corresponds to the observed beat frequencies. MD simulations indicate that the dyes in our constructs lie largely internal to the DNA base stacking region, similar to the native design of biological light harvesting complexes. Observed coherences persist on the timescale of photosynthetic energy transfer yielding further parallels to observed biological coherences, establishing DNA as an attractive scaffold for synthetic light harvesting applications.