The transition from a liquid to a glass in colloidal suspensions of particles interacting through a hard core plus an attractive square-well potential is studied within the mode-coupling-theory framework. When the width of the attractive potential is much shorter than the hard-core diameter, a reentrant behavior of the liquid-glass line and a glass-glass-transition line are found in the temperature-density plane of the model. For small well-width values, the glass-glass-transition line terminates in a third-order bifurcation point, i.e., in a A(3) (cusp) singularity. On increasing the square-well 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 stretching of huge dynamical windows, in particular logarithmic time dependence.
Higher-order glass-transition singularities in colloidal systems with attractive interactions
Zaccarelli E
2001
Abstract
The transition from a liquid to a glass in colloidal suspensions of particles interacting through a hard core plus an attractive square-well potential is studied within the mode-coupling-theory framework. When the width of the attractive potential is much shorter than the hard-core diameter, a reentrant behavior of the liquid-glass line and a glass-glass-transition line are found in the temperature-density plane of the model. For small well-width values, the glass-glass-transition line terminates in a third-order bifurcation point, i.e., in a A(3) (cusp) singularity. On increasing the square-well 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 stretching of huge dynamical windows, in particular logarithmic time dependence.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
