Plasmons in Z2 Topological Insulators
arXiv:2205.04062 · doi:10.1103/PhysRevB.107.155414
Abstract
We study plasmonic excitations in the Kane-Mele model, a two-dimensional Z2 topological insulator on the honeycomb lattice, using the random phase approximation (RPA). In the topologically non-trivial phase, the model has conducting edge states that traverse the bulk energy gap and display spin-momentum-locking. Such a state of matter is called the quantum spin hall (QSH) phase, which is robust against time-reversal (TR) invariant perturbations. We find that in the QSH phase, gapless spin-polarized plasmons can be excited on the edges of the system. The propagation of these plasmons is chiral for each individual spin component and shows spin-momentum-locking for both spin components on the same edge. Moreover, we study the effect of external magnetic fields on the gapless edge plasmons. Specifically, out-of-plane magnetic fields delocalize edge plasmons propagating in one direction without affecting the other one, while an in-plane magnetic field can be applied to selectively excite a specific spin-plasmon branch with proper doping or gating to the system. Our findings may have potential applications in novel plasmonic and spintronic devices. We also investigate plasmons in the Kane-Mele model on a finite-sized diamond-shaped nanoflake and observe low-energy plasmons circulating the boundary of the material.
arXiv comment11 pages, 12 figures
References in corpus (39)
- Experimental Observation of Quantum Hall Effect and Berry's Phase in Graphene
- Quantum Spin Hall Effect in Graphene
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Topological Order and the Quantum Spin Hall Effect
- Quantum Spin Hall Insulator State in HgTe Quantum Wells
- Topological Insulators in Three Dimensions
- Topological Insulators with Inversion Symmetry
- A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
- Room-Temperature Quantum Hall Effect in Graphene
- Quantum Spin Hall Effect
- Colloquium: Topological Band Theory
- Electronic States of Graphene Nanoribbons
- Intrinsic and Rashba Spin-orbit Interactions in Graphene Sheets
- Spin-orbit coupling in curved graphene, fullerenes, nanotubes, and nanotube caps
- Spin-orbit gap of graphene: First-principles calculations
- Experimental realization of an intrinsic magnetic topological insulator
- Observation of Dirac plasmons in a topological insulator
- Anisotropic spin relaxation in graphene
- Infrared Topological Plasmons in Graphene
- Engineering Corner States from Two-Dimensional Topological Insulators
- Discovery of switchable weak topological insulator state in quasi-one-dimensional bismuth iodide
- Surface Plasmons and Topological Insulators
- Magnetoplasmons in layered graphene structures
- Bulk and edge spin transport in topological magnon insulators
- Long-lived spin plasmons in a spin-polarized two-dimensional electron gas
- Plasmonic eigenmodes in individual and bow-tie graphene nanotriangles
- Collective excitations on a surface of topological insulator
- Doping dependence of the chemical potential and surface electronic structure in YBa2Cu3O6+x and La2-xSrxCuO4 using hard x-ray photoemission spectroscopy
- Plasmon confinement in fractal quantum systems
- Proposal for a Topological Plasmon Spin Rectifier
- Topological magnon bands for magnonics
- Finite-temperature plasmons, damping and collective behavior for model
- Plasmons in spin polarized graphene: a new way to measure spin polarization
- Surface plasmons in doped topological insulators
- Topological spin-plasma waves
- Localized Plasmons in Topological Insulators
- Plasmons in Two-Dimensional Topological Insulators
- Plasmonic Waveguides from Coulomb-Engineered Two-Dimensional Metals
- Control of Plasmons in Topological Insulators via Local Perturbations