Surface creasing of soft elastic continua as a Kosterlitz-Thouless transition

Harnessing a model from composite materials science, we show how microscopic crease and anticrease features may arise as quasi-particle excitations on the surface of a soft elastic material, where disorder and drive-induced strain fluctuations play the role of thermal fluctuations. These features appear above a critical strain fluctuation at which zero-length crease-anticrease pairs unbind, analogous to vortex unbinding in the Kosterlitz-Thouless transition. Finite-length creases can be described in the same framework. Our predictions for crease surface profiles and onset strain agree with previous experiments, and further tests are proposed.