Photonic Topological Anderson Insulators

Abstract

The hallmark property of two-dimensional topological materials is the incredible robustness of the quantized Hall conductivity to disorder. That robustness arises from the fact that in the topological band gap, transport can occur only along the edges modes, which are immune to scattering. However, for sufficiently strong disorder, the band gap closes and the system becomes topologically trivial as all states become localized, such that all transport vanishes -- in accordance with Anderson localization. It therefore came as a surprise when it was suggested that, for a two-dimensional quantum spin-Hall topological system, the opposite could occur. In so-called topological Anderson insulators, the emergence of protected edge states and quantized transport is caused by the introduction of disorder. However, to date, the observation of the topological Anderson insulator phase has been elusive. In this article, we report the first experimental demonstration of a topological Anderson insulator. We do that in a photonic implementation: an array of helical, evanescently-coupled waveguides in a detuned honeycomb geometry. Under proper conditions, adding on-site disorder, in the form of random variations in the refractive index contrast defining the waveguides, drives the system from a trivial phase into a topological state.

20 pages, 4 figures

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Cited by in corpus (23)

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• Photonic Floquet topological insulators in a fractal lattice
• Topological Anderson insulators in two-dimensional non-Hermitian disordered systems
• Bimorphic Floquet Topological Insulators
• Fate of zero modes in a finite Su-Schrieffer-Heeger Model with $\mathcal{P}\mathcal{T}$ Symmetry
• Topological Anderson phase in quasi-periodic waveguide lattices
• Identifying Topological Phase Transitions in Experiments Using Manifold Learning
• Floquet topological insulator laser
• Topological Anderson insulators induced by random binary disorders
• Topological Anderson amorphous insulator
• Topological Anderson insulators in an Ammann-Beenker quasicrystal and a snub-square crystal
• Valley Hall edge solitons in a photonic graphene
• Phase transitions and scale invariance in topological Anderson insulators
• Topological transitions and Anderson localization of light in disordered atomic arrays
• Simulating topological materials with photonic synthetic dimensions in cavities
• Topological Protection and Control of Quantum Markovianity
• Type-II Dirac photonic lattices
• Maryland model in optical waveguide lattices
• Signature of edge states in resonant wave scattering
• Dynamics of transmission in disordered topological insulators
• Topological phenomena demonstrated in photorefractive photonic lattices
• Topological Photonics on a Small Scale
• Disorder-induced chiral and helical Majorana edge modes in a two-dimensional Ammann-Beenker quasicrystal