Figure 1

(a) The assumed temperature profile $T(\mathbf{x},t)$. The parameter $\delta$ corresponds to the width of the spatial region defined by $T_g<T<T_c$. (b) Mobility field profile ${log}_{10}[\Lambda (\mathbf{x},t)]$ with ${\Lambda }_{\max }={10}^2$, ${\Lambda }_{\min }={10}^{-8}$, and ${\Lambda }_h(\mathbf{x})={10}^{n(\mathbf{x})}$, where $n(\mathbf{x})$ is randomly selected from a uniform distribution defined on the interval [$-5,1$], for all $\mathbf{x}$—these values of ${\Lambda }_{\max }$, ${\Lambda }_{\min }$, and ${\Lambda }_h(\mathbf{x})$ are used throughout this Letter. The volume of a single lattice site is selected to be $d\mathbf{x}={0.5}^2$. Assuming $R_g\approx 10\mathrm{nm}$, we have $d\mathbf{x}\approx (5\mathrm{nm}{)}^2$, so that the size of the dynamic heterogeneities modeling by ${\Lambda }_h(\mathbf{x})$ are consistent with previous work [10]. (c) Partial 2D plot of ${log}_{10}[\Lambda (\mathbf{x},t)]$ with ${\Lambda }_{\max }$, ${\Lambda }_{\min }$, and ${\Lambda }_h(\mathbf{x})$ specified above. The central speckled area is the region of significant mobility heterogeneities. The light- and dark-colored areas are the regions of fast and slow relaxation, respectively. The arrow indicates the positive $x$ direction.Reuse & Permissions

Figure 2

Partial 2D SCFT mobility field and composition snapshots of a $V={128}^2$ $AB$ diblock melt with $f=0.5$ and $\chi N=15$ simulated on a periodic ${256}^2$ square lattice. Time is in units of $W_{-}$-update time steps with $\Delta t=1$. The system is subjected to the time-dependent mobility gradient specified in Fig. 1. The first row of images illustrates the mobility field $\Lambda$ at an early time, and the second row of images illustrates the corresponding composition of the melt ${\varphi }_A$. The third row of images illustrates the composition of the melt ${\varphi }_A$ after the mobility gradient passed and the system was allowed to further relax. All relevant system parameters are specified in the figure. Case A represents a fully relaxed simulation with a uniform mobility field $\Lambda (\mathbf{x})={10}^2$. Cases B to E represent a series of simulations with various gradient velocities $v_x$ and gradient widths $\delta$. For case F, the system is subjected to a mobility field characterized by significant heterogeneities ${\Lambda }_h(\mathbf{x})$, as specified in Fig. 1. For all frames, we plot 25% of the total simulation space, and the arrows indicate the positive $x$ direction.Reuse & Permissions