Is disorder both friend and foe to melting of Wigner-Mott insulators? – Part 2

Building on the arguments presented in part one, we further demonstrate the stabilizing role of disorder through explicit microscopic model calculations. These show that disorder can significantly stabilize Wigner crystals, allowing them to persist to much higher temperatures and densities than in the clean (disorder-free) limit. As discussed in the first part, bond fluctuations play a central role in the stabilization mechanism. We again utilize a local marker to characterize the spatial features of phase coexistence. We argue that in two dimensions, disorder causes the melting transition to become significantly "smeared," resulting in spatial coexistence of solid-like and liquid-like regions. This phenomenon has been directly observed in recent STM experiments. Our results offer a new physical picture for the melting of Wigner-Mott solids in two dimensions—akin to a Mott-Hubbard model with spatially varying local electronic bandwidth.