Quantum suppression of the Rayleigh instability in nanowires

A linear stability analysis of metallic nanowires is performed in the free-electron model using quantum chaos techniques. It is found that the classical instability of a long wire under surface tension can be completely suppressed by electronic shell effects, leading to stable cylindrical configurations whose electrical conductance is a magic number 1,3,5,6,... times the quantum of conductance. Our results are quantitatively consistent with recent experiments with alkali metal nanowires.