Acoustic spin-Chern insulator induced by synthetic spin-orbit coupling with spin conservation breaking

Abstract

Topologically protected surface modes of classical waves hold the promise to enable a variety of applications ranging from robust transport of energy to reliable information processing networks. The integer quantum Hall effect has delivered on that promise in the electronic realm through high-precision metrology devices. However, both the route of implementing an analogue of the quantum Hall effect as well as the quantum spin Hall effect are obstructed for acoustics by the requirement of a magnetic field, or the presence of fermionic quantum statistics, respectively. Here, we use a two-dimensional acoustic crystal with two layers to mimic spin-orbit coupling, a crucial ingredient of topological insulators. In particular, our setup allows us to free ourselves of symmetry constraints as we rely on the concept of a non-vanishing "spin" Chern number. We experimentally characterize the emerging boundary states which we show to be gapless and helical. Moreover, in an H-shaped device we demonstrate how the transport path can be selected by tuning the geometry, enabling the construction of complex networks.

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Cited by in corpus (18)

• Topological acoustics
• Experimental characterization of fragile topology in an acoustic metamaterial
• Hybrid-order topological insulators in a phononic crystal
• Acoustic square-root topological insulators
• Floquet generation of Second Order Topological Superconductor
• Ln2(SeO3)2(SO4)(H2O)2 (Ln = Sm, Dy, Yb): A Mixed-Ligand Pathway to New Lathanide (III) Multifunctional Materials Featuring Nonlinear Optical and Magnetic Anisotropy Properties
• Topological materials for full-vector elastic waves
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• Synthetic Mechanical Lattices with Synthetic Interactions
• Higher Chern numbers in multilayer ($\mathcal{N}\ge 2$) Lieb lattices: Topological transitions and quadratic band crossing lines
• Topologically invisible defects in chiral mirror lattices
• All hourglass bosonic excitations in the 1651 magnetic space groups and 528 magnetic layer groups
• Imaginary spin-orbital coupling in parity-time symmetric systems with momentum-dependent gain and loss
• Topological characterization of modified Kane-Mele-Rashba models via local spin Chern marker
• Quantum anomalous Hall conductivity in altermagnets under applied magnetic field
• Acoustic topological Anderson insulators
• Dynamical transition in non-Hermitian Chern insulator
• Interfacial Line Energy of a Topological Phase