Glass susceptibility: Growth kinetics and saturation under shear

Abstract

We study the growth kinetics of glassy correlations in a structural glass by monitoring the evolution, within mode-coupling theory, of a suitably defined three-point function chi(C) (t, t(w)) with time t and waiting time t(w). From the complete wave-vector-dependent equations of motion for domain growth, we pass to a schematic limit to obtain a numerically tractable form. We find that the peak value chi(P)(C) of chi(C) (t, t(w)), which can be viewed as a correlation volume, grows as t(w)(0.5), and the relaxation time as t(w)(0.8), following a quench to a point deep in the glassy state. These results constitute a theoretical explanation of the simulation findings of Parisi [J. Phys. Chem. B 103, 4128 (1999)] and Kob and Barrat [Phys. Rev. Lett. 78, 4581 (1997)], and they are also in qualitative agreement with Parsaeian and Castillo [Phys. Rev. E 78, 060105(R) (2008)]. On the other hand, if the quench is to a point on the liquid side, the correlation volume grows to saturation. We present a similar calculation for the growth kinetics in a p-spin spin glass mean-field model where we find a slower growth, chi(P)(C) similar to t(w)(0.13). Further, we show that a shear rate (gamma) over dot cuts off the growth of glassy correlations when t(w) similar to 1/(gamma) over dot for quench in the glassy regime and t(w) = min(t(r),1/(gamma) over dot) in the liquid, where t(r) is the relaxation time of the unsheared liquid. The relaxation time of the steady-state fluid in this case is alpha(gamma) over dot(-0.8).

Publication
PHYSICAL REVIEW E 94, (2016).
Date
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