Topological dislocation modes in three-dimensional acoustic topological insulators

Abstract

Dislocations are ubiquitous in three-dimensional solid-state materials. The interplay of such real space topology with the emergent band topology defined in reciprocal space gives rise to gapless helical modes bound to the line defects. This is known as bulk-dislocation correspondence, in contrast to the conventional bulk-boundary correspondence featuring topological states at boundaries. However, to date rare compelling experimental evidences are presented for this intriguing topological observable, owing to the presence of various challenges in solid-state systems. Here, using a three-dimensional acoustic topological insulator with precisely controllable dislocations, we report an unambiguous experimental evidence for the long-desired bulk-dislocation correspondence, through directly measuring the gapless dispersion of the one-dimensional topological dislocation modes. Remarkably, as revealed in our further experiments, the pseudospin-locked dislocation modes can be unidirectionally guided in an arbitrarily-shaped dislocation path. The peculiar topological dislocation transport, expected in a variety of classical wave systems, can provide unprecedented controllability over wave propagations.

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Cited by in corpus (13)

• Topological acoustics
• Observation of degenerate zero-energy topological states at disclinations in an acoustic lattice
• Realization of a Z classified chiral-symmetric higher-order topological insulator in a coupling-inversion acoustic crystal
• Observation of Topological Corner State Arrays in Photonic Quasicrystals
• Quasicrystalline second-order topological semimetals
• Floquet Mode Resonance: Trapping light in the bulk mode of a Floquet topological insulator by quantum self-interference
• Topological gap solitons in Rabi Su-Schrieffer-Heeger lattices
• Emergent metallicity at the grain boundaries of higher-order topological insulators
• Delocalized spectra of Landau operators on helical surfaces
• Topological magnonic dislocations modes
• Quantized crystalline-electromagnetic responses in insulators
• Fragile dislocation modes in obstructed atomic topological phases
• Topological Dislocation Response in Elementary Semiconductors