Unconventional bound states in the continuum from metamaterial induced electron-acoustic plasma waves

Abstract

Photonic bound states in the continuum are spatially localised modes with infinitely long lifetimes that exist within a radiation continuum at discrete energy levels. These states have been explored in various systems where their emergence is either guaranteed by crystallographic symmetries or due to topological protection. Their appearance at desired energy levels is, however, usually accompanied by non-BIC resonances, from which they cannot be disentangled. Here, we propose a new generic mechanism to realize bound states in the continuum that exist by first principles free of other resonances and are robust upon parameter tuning. The mechanism is based on the fundamental band in double-net metamaterials, which provides vanishing homogenized electromagnetic fields. We predict two new types of bound states in the continuum: i) generic modes confined to the metamaterial bulk, mimicking electronic acoustic waves in a hydrodynamic double plasma, and ii) topological surface bound states in the continuum.

References in corpus (7)

• Topological nature of bound states in the radiation continuum
• High-Q supercavity modes in subwavelength dielectric resonators
• Generation and Annihilation of Topologically-Protected Bound States in the Continuum and Circularly-Polarized States by Symmetry Breaking
• A group theoretical route to deterministic Weyl points in chiral photonic lattices
• Helical bound states in the continuum of the edge states in two dimensional topological insulators
• Light tunneling anomaly in interlaced metallic wire meshes
• Metamaterials with index ellipsoids at arbitrary k-points