Higher-order glass-transition singularities in colloidal systems with attractive interactions - art. no. 011401

The transition from a liquid to a glass in colloidal suspensions of particl es interacting through a hard core plus an attractive square-well potential is studied within the mode-coupling-theory framework. When the width of th e attractive potential is much shorter than the hard-core diameter, a reent rant behavior of the liquid-glass line and a glass-glass-transition line ar e found in the temperature-density plane of the model. For small well-width values, the glass-glass-transition line terminates in a third-order bifurc ation point, i.e., in a A(3) (cusp) singularity. On increasing the square-w ell width, the glass-glass line disappears, giving rise to a fourth-order A (4) (swallow-tail) singularity at a critical well width. Close to the A(3) and A(4) singularities the decay of the density correlators shows stretchin g of huge dynamical windows, in particular logarithmic time dependence.