Designer disordered materials with large complete photonic band gaps
Until recently, the only materials known to have sizeable complete photonic band gaps were photonic crystals, periodic structures, and it was generally assumed that long-range periodic order was instrumental in the photonic band gap (PBG) formation.
In challenging this assumption and answering whether non-periodic PBG materials with unrestricted symmetries and therefore even richer physical properties exist, we have discovered a new class of materials with large complete band gaps, namely, hyperuniform non-crystallographic structures.
This class of materials characterized by suppressed density fluctuations (hyperuniformity) includes isotropic, translationally-disordered structures and quasicrystals with crystallographically forbidden rotational symmetries. We have also invented a universal protocol and a highly-efficient computational framework for mapping point patterns into space tessellations that enable the optimal design of both periodic and non-periodic PBG structures. Moreover, we have shown that all known PBG materials, periodic, quasiperiodic and disordered, are part of a same general class of hyperuniform structures, being distinguished by various degrees of hyperuniformity.
The PBG results from a combination of global hyperuniformity, uniform local topology, and short-range geometric order. Due to their distinctive optical and structural properties, non-crystallographic PBG materials are expected to facilitate unprecedented capabilities for controlling light, such as waveguiding with arbitrary bending angle and highly-efficient isotropic emission, with great impact for information processing, energy harvesting, sensing, and lighting applications. Also, our discovery has broad physical implications beyond photonic materials. It shows that it is possible to produce different types of hyperuniform structures and, consequently, many distinct classes of novel electronic or phononic systems.