2011/02/08 by Samir El Shawish, Jure Dobnikar, Emmanuel Trizac · 1 citation
Physics and Astronomy · #cond-mat.soft
paper · pdf · doi:10.1103/physreve.83.041403
published as Phys. Rev. E 83 041403 (2011) · 14 pages, 13 figures
arxiv created 2011/02/08 · arxiv updated 2015/05/27
We theoretically and numerically studied ordering of "colloidal ionic clusters" on periodic substrate potentials as those generated by optical trapping. Each cluster consists of three charged spherical colloids: two negatively and one positively charged. The substrate is a square or rectangular array of traps, each confining one such cluster. By varying the lattice constant from large to small, the observed clusters are first rod-like and form ferro- and antiferro-like phases, then they bend into a banana-like shape and finally condense into a percolated structure. Remarkably, in a broad parameter range between single-cluster and percolated structures, we have found stable supercomplexes composed of six colloids forming grape-like or rocket-like structures. We investigated the possibility of macroscopic pattern switching by applying external electrical fields.