Colloids are ideal for studying the general problem of complex matter in systems with competing interactions and can have implications for the understanding of both soft and hard condensed matter systems. When colloids are exposed to a periodic optical trap array, the competition between the symmetry of the array and the triangular ordering preferred by the colloids produces a remarkably rich variety of static and dynamical states. The ordering of the equilibrium ground states can be tuned to produce the same symmetries as Ising, Potts, and spin glass systems, while nonequilibrium phenomena such as collective switching dynamics, martensitic transitions, and liquid crystal-like behaviors can also be achieved. I show that colloids with intrinsic competing interactions can produce novel self-organized stripe, labyrinth and network structures as well as artificial nuclei. These systems can have unusual intermediate liquid states in which the patterns are internally liquidlike while the overall pattern remains solid.
Coffee and cookies before the presentation at 3:15 pm, and refreshments after the presentation will both be served in Room 128.