A perspective of twisted photonic structures

TL;DR

This paper reviews recent advances in twisted photonic structures, highlighting their unique phenomena, potential applications, and the interplay of quantum and electromagnetic couplings in nano-optics.

Contribution

It provides a comprehensive overview of twisted photonic systems, comparing them with moire superlattices in condensed matter physics, and discusses future research directions.

Findings

Rich phenomena in nano-optics due to interlayer coupling

Potential for novel photonic applications

Emerging topics and fundamental challenges

Abstract

Moire superlattices-twisted van der Waals (vdW) structures with small angles-are attracting increasing attention in condensed matter physics, due to important phenomena revealed therein, including unconventional superconductivity, correlated insulating states, and ferromagnetism. Moire superlattices are typically comprised of atomic layers of vdW materials where the exotic physics arises from the quantum electronic coupling between adjacent atomic layers. Recently, moire electronics has motivated their photonic counterparts. In addition to vdW materials, twisted photonic systems can also be comprised of metamaterials, metasurfaces, and photonic crystals, mediated by interlayer electromagnetic coupling instead. The interplay between short-ranged interlayer quantum and long-ranged electromagnetic coupling in twisted structures are expected to yield rich phenomena in nano-optics. This perspective reviews recent progress in twisted structures for nanophotonics and outlooks emerging topics, opportunities, fundamental challenges, and potential applications.