On the influence of structural effects on localized density fluctuations in DNA

DNA-based nanomaterials and nanostructures have wide applications in nanomaterials engineering covering the fields from electronic devices and photocatalysis to biosensing, bioimaging, and therapeutics. In particular, DNA nanostructures can be involved in the field of soft matter metamaterials in the terahertz-frequency range. In the present work, we consider terahertz collective atomic dynamics in DNA. Earlier, on the basis of a nonlinear generalized hydrodynamic model, we showed that for excitation wave numbers near the position of the maximum of the static structure factor of the system, structural effects, corresponding to the wave number dependence of the static structure factor, tend to induce delocalization of the initially localized large-amplitude density fluctuations. In the present work, we show that this effect occurs not only in the nonlinear case but also in the linear case, which allows to consider the problem in the framework of linear response theory. These findings might be useful in our understanding of large-amplitude density oscillations in DNA-based nanostructures and nanomaterials in the terahertz-frequency range.