scholarly journals Topological-Insulator-Based Gap-Surface Plasmon Metasurfaces

Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 40
Author(s):  
Andreas Aigner ◽  
Stefan A. Maier ◽  
Haoran Ren
Keyword(s):  
Surface Plasmon ◽  
Topological Insulator ◽  
Electromagnetic Waves ◽  
Beam Steering ◽  
Near Field ◽  
Surface States ◽  
Visible Spectrum ◽  
Visible Spectral Range ◽  
Far Field ◽  
Protected Surface

Topological insulators (TIs) have unique highly conducting symmetry-protected surface states while the bulk is insulating, making them attractive for various applications in condensed matter physics. Recently, topological insulator materials have been tentatively applied for both near- and far-field wavefront manipulation of electromagnetic waves, yielding superior plasmonic properties in the ultraviolet (UV)-to-visible wavelength range. However, previous reports have only demonstrated inefficient wavefront control based on binary metasurfaces that were digitalized on a TI thin film or non-directional surface plasmon polariton (SPP) excitation. Here, we numerically demonstrated the plasmonic capabilities of the TI Bi2Te3 as a material for gap–surface plasmon (GSP) metasurfaces. By employing the principle of the geometric phase, a far-field beam-steering metasurface was designed for the visible spectrum, yielding a cross-polarization efficiency of 34% at 500 nm while suppressing the co-polarization to 0.08%. Furthermore, a birefringent GSP metasurface design was studied and found to be capable of directionally exciting SPPs depending on the incident polarization. Our work forms the basis for accurately controlling the far- and near-field responses of TI-based GSP metasurfaces in the visible spectral range.

scholarly journals Near-field Strong Plasmonic Resonances in Bi1.5Sb0.5Te1.8Se1.2 Topological Insulator Film

2021 ◽  
Author(s):  
Baoshan Guo ◽  
Huan Yao ◽  
Ningwei Zhan ◽  
Lan Jiang
Keyword(s):  
Topological Insulator ◽  
Electromagnetic Waves ◽  
Near Infrared ◽  
Near Field ◽  
Surface States ◽  
Field Energy ◽  
Hole Array ◽  
Infrared Range ◽  
Plasmonic Material ◽  
Edge Surface

Abstract Topological insulators are a new class of quantum materials with metallic (edge) surface states and insulating bulk states. They exhibit various novel electronic and optical properties that make them highly promising electronic, spintronic, and optoelectronic materials. Our report confirms that the topological insulator Bi 1.5 Sb 0.5 Te 1.8 Se 1.2 (BSTS) is also an effective plasmonic material in the visible and near-infrared range. A BSTS film can effectively control transmission and reflection characteristics by changing the period of the hole array. This study determined that a strong resonant surface plasmonic mode at the resonance peak can confine approximately 80% of the electromagnetic field energy is demonstrated. Higher-order (second- and third-order) resonance peaks were also found, which is critical for controlling electromagnetic waves and research into new optoelectronic devices.

Near-Field Tomography and Spectroscopy of Surface States on a Three-Dimensional Topological Insulator

2019 ◽  
Author(s):  
Fabian Sandner ◽  
Fabian Mooshammer ◽  
Markus A. Huber ◽  
Martin Zizlsperger ◽  
Helena Weigand ◽  
...  
Keyword(s):  
Topological Insulator ◽  
Near Field ◽  
Three Dimensional ◽  
Surface States

Surface plasmon resonance (SPR) reflectance imaging: Far-field recognition of near-field phenomena

2012 ◽  
Vol 50 (1) ◽  
pp. 64-73 ◽  
Author(s):  
K.D. Kihm ◽  
S. Cheon ◽  
J.S. Park ◽  
H.J. Kim ◽  
J.S. Lee ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Near Field ◽  
Far Field

scholarly journals Mapping propagation of collective modes in Bi2Se3 and Bi2Te2.2Se0.8 topological insulators by near-field terahertz nanoscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Arianna Aurelia Pogna ◽  
Leonardo Viti ◽  
Antonio Politano ◽  
Massimo Brambilla ◽  
Gaetano Scamarcio ◽  
...  
Keyword(s):  
Topological Insulators ◽  
Near Field ◽  
Surface States ◽  
Longitudinal Optical ◽  
Collective Modes ◽  
Protected Surface ◽  
Topological Surface ◽  
The Rich ◽  
Nano Imaging ◽  
New Research

AbstractNear-field microscopy discloses a peculiar potential to explore novel quantum state of matter at the nanoscale, providing an intriguing playground to investigate, locally, carrier dynamics or propagation of photoexcited modes as plasmons, phonons, plasmon-polaritons or phonon-polaritons. Here, we exploit a combination of hyperspectral time domain spectroscopy nano-imaging and detectorless scattering near-field optical microscopy, at multiple terahertz frequencies, to explore the rich physics of layered topological insulators as Bi2Se3 and Bi2Te2.2Se0.8, hyperbolic materials with topologically protected surface states. By mapping the near-field scattering signal from a set of thin flakes of Bi2Se3 and Bi2Te2.2Se0.8 of various thicknesses, we shed light on the nature of the collective modes dominating their optical response in the 2-3 THz range. We capture snapshots of the activation of transverse and longitudinal optical phonons and reveal the propagation of sub-diffractional hyperbolic phonon-polariton modes influenced by the Dirac plasmons arising from the topological surface states and of bulk plasmons, prospecting new research directions in plasmonics, tailored nanophotonics, spintronics and quantum technologies.

scholarly journals Time Reversal in Subwavelength-Scaled Resonant Media: Beating the Diffraction Limit

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Fabrice Lemoult ◽  
Abdelwaheb Ourir ◽  
Julien de Rosny ◽  
Arnaud Tourin ◽  
Mathias Fink ◽  
...  
Keyword(s):  
Time Reversal ◽  
Electromagnetic Waves ◽  
Spatial Information ◽  
Near Field ◽  
Finite Size ◽  
Diffraction Limit ◽  
Far Field ◽  
Underwater Communications ◽  
Focusing Effect ◽  
Propagation Medium

Time reversal is a physical concept that can focus waves both spatially and temporally regardless of the complexity of the propagation medium. Time reversal mirrors have been demonstrated first in acoustics, then with electromagnetic waves, and are being intensively studied in many fields ranging from underwater communications to sensing. In this paper, we will review the principles of time reversal and in particular its ability to focus waves in complex media. We will show that this focusing effect depends on the complexity of the propagation medium rather than on the time reversal mirror itself. A modal approach will be utilized to explain the physical mechanism underlying the concept. A particular focus will be given on the possibility to break the diffraction barrier from the far field using time reversal. We will show that finite size media made out of coupled subwavelength resonators support modes which can radiate efficiently in the far field spatial information of the near field of a source. We will show through various examples that such a process, due to reversibility, permits to beat the diffraction limit using far field time reversal, and especially that this result occurs owing to the broadband inherent nature of time reversal.

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