Observation of Topological Phase Transitions in Photonic Quasicrystals

TL;DR

This paper demonstrates the direct observation of bulk topological phase transitions in photonic quasicrystals and confirms the topological equivalence between Harper and Fibonacci quasicrystals through experimental boundary analysis.

Contribution

It introduces a method to observe bulk phase transitions in photonic quasicrystals and verifies topological equivalence between different quasicrystal models.

Findings

Bulk phase transitions observed in photonic quasicrystals.

Confirmed topological equivalence between Harper and Fibonacci quasicrystals.

Established a smooth boundary method for topological analysis.

Abstract

Topological insulators and topological superconductors are distinguished by their bulk phase transitions and gapless states at a sharp boundary with the vacuum. Quasicrystals have recently been found to be topologically nontrivial. In quasicrystals, the bulk phase transitions occur in the same manner as standard topological materials, but their boundary phenomena are more subtle. In this Letter we directly observe bulk phase transitions, using photonic quasicrystals, by constructing a smooth boundary between topologically distinct one-dimensional quasicrystals. Moreover, we use the same method to experimentally confirm the topological equivalence between the Harper and Fibonacci quasicrystals.