Ultrastable jammed sphere packings with a wide range of particle dispersities

Abstract

We show that for a standard continuously-polydisperse model with particle-diameter distribution $P(\sigma )\propto {\sigma }^{-3}$ and polydispersity index $\Delta$, employing a combination of standard SWAP moves and transient degree of freedom (TDOF) moves during a Lubachevsky-Stillinger-like particle-growth process dramatically increases the generated packings' jamming densities ${\varphi }_{\mathrm{J}}(\Delta )$ and coordination numbers $Z_{\mathrm{J}}(\Delta )$, for a wide range of $\Delta$. The fractional increase in ${\varphi }_{\mathrm{J}}(\Delta )$ obtained by employing these moves first increases rapidly with $\Delta$, then plateaus at $6-7\%$ over the range $0.10\lesssim \Delta \le 50$; the obtained ${\varphi }_{\mathrm{J}}$ are as high as $0.747$ (for $\Delta =0.50$). These density increases are achieved without producing clearly-noticeable crystallization or increased fractionation, despite the fact that the packings are quite hyperstatic for all $\Delta >0$. SWAP and TDOF moves also reduce packings' rattler populations by as much as 99% and increase their bulk moduli by as much as 80%.

Extensively revised in response to reviewer comments