Phononic Stiefel-Whitney topology with corner vibrational modes in two-dimensional Xenes and ligand-functionalized derivatives
arXiv:2211.05663 · doi:10.1103/PhysRevB.106.L201406
Abstract
Two-dimensional (2D) Stiefel-Whitney (SW) insulator is a fragile topological state characterized by the second SW class in the presence of space-time inversion symmetry. So far, SWIs have been proposed in several electronic materials but seldom in phononic systems. Here we recognize that a large class of 2D buckled honeycomb crystals termed Xenes and their ligand-functionalized derivatives realize the nontrivial phononic SW topology. The phononic SWIs are identified by a nonzero second SW number , associated with gaped edge states and robust topological corner modes. Despite the versatility of electronic topological properties in these materials, the nontrivial phononic SW topology is mainly attributed to the double band inversion between in-plane acoustic and out-of-plane optical bands with opposite parities due to the structural buckling of the honeycomb lattice. Our findings not only reveal an overlooked phononic topological property of 2D Xene-related materials, but also afford abundant readily synthesizable material candidates with simple phononic spectra for further experimental studies of phononic SW topology physics.
arXiv commentPhys. Rev. B (in press)
References in corpus (42)
- Topological Insulators with Inversion Symmetry
- Control of graphene's properties by reversible hydrogenation
- WannierTools: An open-source software package for novel topological materials
- Quantum Spin Hall Effect in Silicene
- Quantized Electric Multipole Insulators
- Epitaxial Growth of Two-Dimensional Stanene
- Higher-Order Topological Insulators
- Germanene: a novel two-dimensional Germanium allotrope akin to Graphene and Silicene
- Large-gap quantum spin Hall insulators in tin films
- -dimensional edge states of rotation symmetry protected topological states
- Valley-Polarized Metals and Quantum Anomalous Hall Effect in Silicene
- Bismuthene on a SiC Substrate: A Candidate for a New High-Temperature Quantum Spin Hall Paradigm
- Reflection symmetric second-order topological insulators and superconductors
- Observation of tunable bandgap and anisotropic Dirac semimetal state in black phosphorus
- Higher-order topological insulators and semimetals on the breathing Kagome and pyrochlore lattices
- Dirac Semimetals in Two Dimensions
- Failure of Nielsen-Ninomiya theorem and fragile topology in two-dimensional systems with space-time inversion symmetry: application to twisted bilayer graphene at magic angle
- Higher-Order Topology, Monopole Nodal Lines, and the Origin of Large Fermi Arcs in Transition Metal Dichalcogenides XTe (X=Mo,W)
- Two-dimensional second-order topological insulator in graphdiyne
- Prediction of Near-Room-Temperature Quantum Anomalous Hall Effect on Honeycomb Materials
- Higher-Order Topological Insulator in Twisted Bilayer Graphene
- Band Topology and Linking Structure of Nodal Line Semimetals with Z2 Monopole Charges
- Functionalized Germanene as a Prototype of Large-Gap Two-Dimensional Topological Insulators
- Minimal model for higher-order topological insulators and phosphorene
- Epitaxial Synthesis of Blue Phosphorene
- Two-dimensional higher-order topology in monolayer graphdiyne
- Unified theory of PT and CP invariant topological metals and nodal superconductors
- Liganded Xene as a Prototype of Two-Dimensional Stiefel-Whitney Insulators
- Symmetric Real Dirac Fermions and Semimetals
- First Principles Calculations for Topological Quantum Materials
- Experimental evidence of monolayer arsenene: An exotic two-dimensional semiconducting material
- Fractional corner charges in spin-orbit coupled crystals
- Boundary criticality of -invariant topology and second-order nodal-line semimetals
- Symmetry representation approach to topological invariants in -symmetric systems
- Stiefel-Whitney classes and topological phases in band theory
- Introduction to the Physics of Silicene and other 2D Materials
- Second Order Topological Insulator State in Hexagonal Lattices and its Abundant Material Candidates
- Kekule Lattice in Graphdiyne: Coexistence of Phononic and Electronic Higher-Order Band Topology
- Phononic real Chern insulator with protected corner modes in graphynes
- Buckled honeycomb group--- symmetric higher order topological insulators
- Second-order and real Chern topological insulator in twisted bilayer -graphyne
- Topological edge and corner states and fractional corner charges in blue phosphorene