Abstract
We optically drive a trapped microscale probe through entangled DNA at rates up to the disentanglement rate (), then remove the trap and track subsequent probe recoil motion. We identify a unique crossover to the nonlinear regime at . Recoil dynamics display rate-dependent dilation and complex power-law healing of the reptation tube. The force response during strain exhibits key nonlinear features such as shear thinning and yielding with power-law rate dependence. Our results, distinctly nonclassical and in accord with recent theoretical predictions, reveal molecular dynamics governed by individual stress-dependent entanglements rather than chain stretching.
- Received 29 April 2014
DOI:https://doi.org/10.1103/PhysRevLett.113.098303
© 2014 American Physical Society