Amorphous topological insulators constructed from random point sets
By N. Mitchell, L. Nash, D. Hexner, Ari M. Turner, William T. M. Irvine. Nature Physics, 2016
301 citations recorded by the source corpus.
The discovery that the band structure of electronic insulators may be topologically non-trivial has revealed distinct phases of electronic matter with novel properties1,2. Recently, mechanical lattices have been found to have similarly rich structure in their phononic excitations3,4, giving rise to protected unidirectional edge modes5–7. In all of these cases, however, as well as in other topological metamaterials3,8, the underlying structure was finely tuned, be it through periodicity, quasi-periodicity or isostaticity. Here we show that amorphous Chern insulators can be readily constructed from arbitrary underlying structures, including hyperuniform, jammed, quasi-crystalline and uniformly random point sets. While our findings apply to mechanical and electronic systems alike, we focus on networks of interacting gyroscopes as a model system. Local decorations control the topology of the vibrational spectrum, endowing amorphous structures with protected edge modes—with a chirality of choice. Using a real-space generalization of the Chern number, we investigate the topology of our structures numerically, analytically and experimentally. The robustness of our approach enables the topological design and self-assembly of non-crystalline topological metamaterials on the micro and macro scale. Whether spatial order is required for structures that support topological modes remains unclear. Amorphous arrangements of interacting gyroscopes suggest that topology arises in materials for which the only design principle is the local connectivity.
Subfields: Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Materials Chemistry
View Paper: https://www.semanticscholar.org/paper/48bed47585e6def2eab066da5bd77c06ec5180c9
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In Atomic and Molecular Physics, and Optics
In Electronic, Optical and Magnetic Materials
In Materials Chemistry
Citations in the corpus
- Topological active matter (2020, background): “As examples, a topological solid can be realized using ball- and-spring models with active feedback control 154,155 or by connecting motorized gyroscopes with springs 156–158 .”
- Tailoring Structure‐Borne Sound through Bandgap Engineering in Phononic Crystals and Metamaterials: A Comprehensive Review (2022, background): “However, few works have introduced these aperiodic lattices [261,482,483] in elastodynamics, and exploration of their dynamical performance with real experimental demonstration is lacking for potential applications such as optomechanics.”