From silicon carbide to the removal of George W Bush by way of Kinlochleven
SiC is a classic case of kinetically limited growth: when a layer material is deposited, the atoms are fixed forever. Thus the observed structures depend on the surface energetics, not those of the bulk This can be modelled with a 1-D Ising model wherein long-range and short range forces compete. The bulk solution of this model is the Devil's Staircase: an equilibrium phase diagram in which various ordered phases are infinitely closely packed as a function of some model parameter. The surface growth model produces all of these phases as a function of depth: producing a tremendous (apparent) complexity which would appear disordered to experiment but is actually zero-entropy. In fact, silicon carbide falls in an uninteresting region of the parameter space, but the model generalises to many applications, including voting strategies in two-party elections. ''Devil's staircase in kinetically limited growth" G. J. Ackland, Phys. Rev. E, cond-mat/0205102
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..