Real-space nanoimaging of THz polaritons in the topological insulator Bi2Se3
arXiv:2107.10791 · doi:10.1038/s41467-022-28791-x
Abstract
Plasmon polaritons in topological insulators attract attention from a fundamental perspective and for potential THz photonic applications. Although polaritons have been observed by THz far-field spectroscopy on topological insulator microstructures, real-space imaging of propagating THz polaritons has been elusive so far. Here, we show spectroscopic THz near-field images of thin Bi2Se3 layers (prototypical topological insulators) revealing polaritons with up to 12 times increased momenta as compared to photons of the same energy and decay times of about 0.48 ps, yet short propagation lengths. From the images we determine and analyze the polariton dispersion, showing that the polaritons can be explained by the coupling of THz radiation to various combinations of Dirac and massive carriers at the Bi2Se3 surfaces, massive bulk carriers and optical phonons. Our work provides critical insights into the nature of THz polaritons in topological insulators and establishes instrumentation and methodology for imaging of THz polaritons.
References in corpus (28)
- Topological Insulators
- Graphene plasmonics
- Gate-tuning of graphene plasmons revealed by infrared nano-imaging
- Optical nano-imaging of gate-tuneable graphene plasmons
- Polaritons in layered 2D materials
- Spintronics and Pseudospintronics in Graphene and Topological Insulators
- Highly confined low-loss plasmons in graphene-boron nitride heterostructures
- Infrared nanoscopy of Dirac plasmons at the graphene-SiO2 interface
- Infrared hyperbolic metasurface based on nanostructured van der Waals materials
- Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
- Observation of Dirac plasmons in a topological insulator
- Photonic crystals for nano-light in moiré graphene superlattices
- Thickness-independent transport channels in topological insulator Bi2Se3 thin films
- Ultra-confined acoustic THz graphene plasmons revealed by photocurrent nanoscopy
- Plasmonics in Dirac systems: from graphene to topological insulators
- Record Surface State Mobility and Quantum Hall Effect in Topological Insulator Thin Films via Interface Engineering
- Optical Nanoimaging of Hyperbolic Surface Polaritons at the Edges of van der Waals Materials
- Phase Resolved Surface Plasmon Interferometry of Graphene
- Probes for Ultrasensitive THz Nanoscopy
- Nanoscale-confined Terahertz Polaritons in a van der Waals Crystal
- Orbital-Selective Spin Texture and its Manipulation in a Topological Insulator
- Surface versus bulk state in topological insulator Bi2Se3 under environmental disorder
- Topological insulators are tunable waveguides for hyperbolic polaritons
- Voltage-controlled surface plasmon-polaritons in double graphene layer structures
- Spin-charge separation of plasmonic excitations in thin topological insulators
- Chiral Spin Mode on the Surface of a Topological Insulator
- Terahertz tuning of Dirac plasmons in BiSe Topological Insulator
- Propagation of Surface Plasmon Polaritons in Thin Films of Topological Insulators