%0 Journal Article
%A Abuín Herráez, Manuel
%T Ultrafast atomic diffusion inducing a reversible (2√3x2√3) R30º  ↔ (√3x√3) R30º transition on Sn/Si (111)∶B
%D 2015
%@ 0031-9007
%U https://hdl.handle.net/20.500.14352/23154
%X Dynamical phase transitions are a challenge to identify experimentally and describe theoretically. Here, we study a new reconstruction of Sn on silicon and observe a reversible transition where the surface unit cell divides its area by a factor of 4 at 250 degrees C. This phase transition is explained by the 24-fold degeneracy of the ground state and a novel diffusive mechanism, where four Sn atoms arranged in a snakelike cluster wiggle at the surface exploring collectively the different quantum mechanical ground states.
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