Enhancement of structural rearrangement in glassy systems under shear flow

Abstract

We extend the analysis of the mean field schematic model recently introduced for the description of glass forming liquids to the case of a supercooled fluid subjected to a shear flow of rate $γ$. After quenching the system to a low temperature $T$, a slow glassy regime is observed before stationarity is achieved at the characteristic time $τ_g$. $τ_g$ is of the order of the usual equilibration time without shear $τ_g^o$ for weak shear, $γτ_g ^o<1$. For larger shear, $γτ_g ^o>1$, local rearrangement of dense regions is instead enhanced by the flow, and $τ_g \simeq 1/(Tγ)$.

8 pages, 3 figures, changed content Pacs{64}{70.Pf}{Glass transitions} Pacs{05}{70.Ln}{Non-equilibrium thermodynamics, irreversible processes} Pacs{83}{50.Ax}{Steady shear flows}