  The mechanism of the collapse of the superhydrophobic state is elucidated for
submerged nanoscale textures forming a three-dimensional interconnected vapor
domain. This key issue for the design of nanotextures poses significant
simulation challenges as it is characterized by diverse time and length scales.
State-of-the-art atomistic rare events simulations are applied for overcoming
the long time scales connected with the large free energy barriers. In such
interconnected surface cavities wetting starts with the formation of a liquid
finger between two pillars. This break of symmetry induces a more gentle bend
in the rest of the liquid-vapor interface, which triggers the wetting of the
neighboring pillars. This collective mechanism, involving the wetting of
several pillars at the same time, could not be captured by previous atomistic
simulations using surface models comprising a small number of pillars (often
just one). Atomistic results are interpreted in terms of a sharp-interface
continuum model which suggests that line tension, condensation, and other
nanoscale phenomena play a minor role in the simulated conditions.
