Higher-order topological insulators
By F. Schindler, A. Cook, M. Vergniory, Zhijun Wang, Stuart S. P. Parkin, Bogdan Andrei Bernevig, Titus Neupert. Science Advances, 2017
1,490 citations recorded by the source corpus.
A new class of materials that are insulating in the bulk and on surfaces but have conducting hinge channels is studied. Three-dimensional topological (crystalline) insulators are materials with an insulating bulk but conducting surface states that are topologically protected by time-reversal (or spatial) symmetries. We extend the notion of three-dimensional topological insulators to systems that host no gapless surface states but exhibit topologically protected gapless hinge states. Their topological character is protected by spatiotemporal symmetries of which we present two cases: (i) Chiral higher-order topological insulators protected by the combination of time-reversal and a fourfold rotation symmetry. Their hinge states are chiral modes, and the bulk topology is Z2-classified. (ii) Helical higher-order topological insulators protected by time-reversal and mirror symmetries. Their hinge states come in Kramers pairs, and the bulk topology is Z-classified. We provide the topological invariants for both cases. Furthermore, we show that SnTe as well as surface-modified Bi2TeI, BiSe, and BiTe are helical higher-order topological insulators and propose a realistic experimental setup to detect the hinge states.
Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry
View Paper: https://www.semanticscholar.org/paper/fd5f97f712d76cae8e4d99c225921d9557c3c4f9
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In Atomic and Molecular Physics, and Optics
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- E. Khalaf
- Ashvin Vishwanath
- H. Po
- Xiujuan Zhang
- Yan-Feng Chen
- Ming-Hui Lu
In Materials Chemistry
- Luka Trifunovic
- P. Brouwer
- E. Khalaf
- Ashvin Vishwanath
- H. Po
- E. Bergholtz
- Xiujuan Zhang
- Haruki Watanabe
Citations in the corpus
- Higher-Order Bulk-Boundary Correspondence for Topological Crystalline Phases (2018, background): “Topological crystalline insulators with second-order boundary states were theoretically predicted for models with certain magnetic symmetries [28], mirror symmetry [28,30], and rotation and inversion symmetries [20,29,31,41–43].”
- Topological superconductivity in two-dimensional altermagnetic metals (2023, methodology): “Since the Hamiltonian does not have the C 4 z rotational symmetry or the time-reversal symmetry but has the C 4 z T symmetry, the Dirac mass m ( x b ) will take opposite signs on two nearby edges related by C 4 z rotation 87 .”
- Symmetry Indicators and Anomalous Surface States of Topological Crystalline Insulators (2017, background): “[20] Frank Schindler, Ashley M Cook, Maia G Vergniory, Zhi-”
- Observation of second-order topological insulators in sonic crystals (2018, background): “Recently, by gapping out the edge states of topological insulators, HOTIs are created, where robust corner or hinge states emerge in the edge gap due to topological mechanisms [24-35].”