Jaeuk Kim, University of Texas at Austin | Advanced Materials

Exotic correlated disorder can make materials transparent: This artwork is inspired by our work “Nonlocal Effective Electromagnetic Wave Characteristics of Composite Media: Beyond the Quasistatic Regime,” supported by AFOSRP Grant No. FA9550-18-1-0514. In this work, we derived nonlocal strong-contrast approximations for the dynamic effective dielectric constant of disordered two-phase media that account for microstructural information at the two-point level. The resulting approximations can apply to a wide class of composite microstructures and accurately capture their effective wave characteristics due to correlated disorder. We demonstrated that these approximations are accurate beyond the traditional long-wavelength regime by comparing them with finite-difference time-domain (FDTD) simulation results. The top and bottom panels illustrate the simulated electric fields traveling through two disordered 2D packings, i.e., equilibrium hard disks and stealthy hyperuniform packings. These packings are depicted by black dashed or green solid circles, respectively. The middle panel shows how the electric field decays as it travels through two media: the black dashed curve and green solid one depict the electric fields on the upper and lower panels, respectively. This artwork demonstrates that one can control effective wave characteristics like transmittance by engineering the correlated disorder. Contributors: Jaeuk Kim and Salvatore Torquato