Engineering Fragile Topology in Photonic Crystals: Topological Quantum Chemistry of Light

Understand

In recent years, there have been rapid advances in the parallel fields of electronic and photonic topological crystals.

• Topological photonic crystals in particular show promise for coherent transport of light and quantum information at macroscopic scales.
• In this work, we apply for the first time the recently developed theory of "Topological quantum chemistry" to the study of band structures in photonic crystals.
• This method allows us to design and diagnose topological photonic band structures using only group theory and linear algebra.