Distinguished Lecturer Series - Event Details
A periodically sheared non-Brownian suspension undergoes collisions which allow the particles to explore new configurations. Below a critical strain the system evolves and arranges itself until collisions no longer occur and an absorbing state is reached. A
simple model “Random Organization” well describes the process. We have studied similar phenomena in granular systems where limit cycles
rather than reversible paths are found as absorbing states. Recent work by Hexmer and Levine show that at criticality absorbing state
systems produce hyperuniform particle correlations. Together we have most recently found that reactivating, “kicking”, the absorbing
state leads to a configuration tending toward to the uniformity of a crystal but with no periodicity or long range order.Hyperuniform systems have particle number fluctuations which grow
less rapidly with window size than do random systems. Torquato and Steinhardt suggested that hyperuniformity rather than periodicity is
responsible for spectral gaps in wavelike materials. We have constructed Hyperuniform disordered systems (HUDS) on a cm
(microwave) and micron (IR) scale and find large isotropic photonic bandgaps. Further we have shown that such HUDS photonic materials can be
modified to allow arbitrary waveguides, switching and resonant cavities.