(552d) Topological Transitions in Densely Packed Anisotropic Colloids

It has been long known that there exist topologically protected phases in strongly coupled systems dominated by quantum effects. Recently, analogous phases have been discovered in classical systems of mechanical metamaterials. Here, we demonstrate the existence of topologically protected phases in systems of densely-packed, hard, anisotropic colloids. Previously reported transitions in dense packings as a function of the constituent particle shape lead to the existence of topologically protected thermodynamic phases in such systems, which are shown to be stable away from the limit of densest packing, down to packing fractions of about 75%. Our discovery expands the library of topological phases, and realizing these phases in experiment could provide a new means of producing complex soft materials that are resistant to thermal fluctuations, with applications in robust information storage and processing, and plasmonic materials.