Revealing the topology of quasicrystals with a diffraction experiment

Understand

Topological properties of crystals and quasicrystals is a subject of recent and growing interest.

• This Letter reports an experiment where, for certain quasicrystals, these properties can be directly retrieved from diffraction.
• We directly observe, using an interferometric approach, all the topological invariants of finite-length Fibonacci chains in their diffraction pattern.
• We also demonstrate quantitatively the stability of these topological invariants with respect to structural disorder.