scholarly journals Observation of localized magnetic plasmon skyrmions

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Zi-Lan Deng ◽  
Tan Shi ◽  
Alex Krasnok ◽  
Xiangping Li ◽  
Andrea Alù
Keyword(s):  
Near Field ◽  
Real Space ◽  
Wearable Electronics ◽  
Experimental Demonstration ◽  
Spatial Profile ◽  
External Interference ◽  
Flexible Sensors ◽  
And Storage ◽  
Topological Robustness ◽  
Plasmon Polaritons

AbstractOptical skyrmions have recently been constructed by tailoring vectorial near-field distributions through the interference of multiple surface plasmon polaritons, offering promising features for advanced information processing, transport and storage. Here, we provide experimental demonstration of electromagnetic skyrmions based on magnetic localized spoof plasmons (LSP) showing large topological robustness against continuous deformations, without stringent external interference conditions. By directly measuring the spatial profile of all three vectorial magnetic fields, we reveal multiple π-twist target skyrmion configurations mapped to multi-resonant near-equidistant LSP eigenmodes. The real-space skyrmion topology is robust against deformations of the meta-structure, demonstrating flexible skyrmionic textures for arbitrary shapes. The observed magnetic LSP skyrmions pave the way to ultra-compact and robust plasmonic devices, such as flexible sensors, wearable electronics and ultra-compact antennas.

Broadband mid-infrared plasmon-polaritons in metallic-dielectric interfaces

2021 ◽  
Author(s):  
Flávio Feres ◽  
Ingrid Barcelos ◽  
Dario Bahamon ◽  
João Levandoski ◽  
Andrea Mancini ◽  
...  
Keyword(s):  
Surface Plasmon Polariton ◽  
Hexagonal Boron Nitride ◽  
Near Field ◽  
Real Space ◽  
Strong Coupling Regime ◽  
General Effect ◽  
Mid Infrared ◽  
Dielectric Interfaces ◽  
Plasmon Polaritons ◽  
Group Velocities

Abstract We report real-space near-field images of mid-infrared (IR) surface plasmon-polariton (SPP) waves in the insulating/metal/insulating (IMI) heterostructure: hexagonal boron nitride/gold/silicon dioxide (hBN/Au/SiO2). The SPPs are observed in the 750 – 1500 cm-1 (~13.3 – ~6.7 μm) range, feature micrometer-sized wavelengths and propagation lengths (LSPP) exceeding 20 μm at room temperature. Comparatively, real-space mapping of SPP waves in the mid-IR has been shown only in graphene, but with nanometer sized-wavelength and LSPP ~ 10 μm at cryogenic temperatures. Interestingly, we show interference between different polariton types in the IMI since the lower momenta SPPs in the metal surface interfere with higher momenta hyperbolic phonon polaritons (HPhP) in the hBN top layer creating SPP-HPhP overlapped waves. In agreement with theory, we quantify momentum and damping governing the SPP waves. Tunability is discussed upon changing the IMI heterostructure. Our theory predicts SPP group velocities reaching 20 % of the light velocity in vacuum and 0.2 – 0.4 ps lifetimes. We further demonstrate that the SPP waves interact with SiO2 and hBN phonons in the strong coupling regime. As a general effect of the metal/dielectric interface, the mid-IR SPP waves can be compelling for fast metal-based plasmonics, whilst their ability to strongly couple to phonons can be further explored for enhanced sensing in the mid-IR.

scholarly journals Optical skyrmion lattice in evanescent electromagnetic fields

Science ◽  
2018 ◽  
Vol 361 (6406) ◽  
pp. 993-996 ◽  
Author(s):  
S. Tsesses ◽  
E. Ostrovsky ◽  
K. Cohen ◽  
B. Gjonaj ◽  
N. H. Lindner ◽  
...  
Keyword(s):  
Electromagnetic Fields ◽  
Domain Walls ◽  
Near Field ◽  
Topological Defects ◽  
High Energy ◽  
Magnetic Storage ◽  
Solid State Physics ◽  
Physical Systems ◽  
And Storage ◽  
Plasmon Polaritons

Topological defects play a key role in a variety of physical systems, ranging from high-energy to solid-state physics. A skyrmion is a type of topological defect that has shown promise for applications in the fields of magnetic storage and spintronics. We show that optical skyrmion lattices can be generated using evanescent electromagnetic fields and demonstrate this using surface plasmon polaritons, imaged by phase-resolved near-field optical microscopy. We show how the optical skyrmion lattice exhibits robustness to imperfections while the topological domain walls in the lattice can be continuously tuned, changing the spatial structure of the skyrmions from bubble type to Néel type. Extending the generation of skyrmions to photonic systems provides various possibilities for applications in optical information processing, transfer, and storage.

Ultra-broadband unidirectional launching of surface plasmon polaritons by a double-slit structure beyond the diffraction limit

Nanoscale ◽  
2014 ◽  
Vol 6 (22) ◽  
pp. 13487-13493 ◽  
Author(s):  
Jianjun Chen ◽  
Chengwei Sun ◽  
Hongyun Li ◽  
Qihuang Gong
Keyword(s):  
Surface Plasmon ◽  
Surface Plasmon Polaritons ◽  
Near Field ◽  
Diffraction Limit ◽  
Plasmonic Waveguide ◽  
Plasmon Polaritons ◽  
Double Slit

Based on the near-field interference of two slit apertures in a subwavelength plasmonic waveguide, an ultra-broadband unidirectional SPP launcher beyond the diffraction limit was experimentally realized. This ultra-small SPP launcher has important applications in high-integration plasmonic circuits.

scholarly journals Direct quantification of topological protection in symmetry-protected photonic edge states at telecom wavelengths

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Sonakshi Arora ◽  
Thomas Bauer ◽  
René Barczyk ◽  
Ewold Verhagen ◽  
L. Kuipers
Keyword(s):  
Near Field ◽  
Edge States ◽  
Quantum Networks ◽  
Hall Effects ◽  
Upper Limits ◽  
On Chip ◽  
Symmetry Protected ◽  
Topological Robustness ◽  
Direct Quantification ◽  
Sub Wavelength

AbstractTopological on-chip photonics based on tailored photonic crystals (PhCs) that emulate quantum valley-Hall effects has recently gained widespread interest owing to its promise of robust unidirectional transport of classical and quantum information. We present a direct quantitative evaluation of topological photonic edge eigenstates and their transport properties in the telecom wavelength range using phase-resolved near-field optical microscopy. Experimentally visualizing the detailed sub-wavelength structure of these modes propagating along the interface between two topologically non-trivial mirror-symmetric lattices allows us to map their dispersion relation and differentiate between the contributions of several higher-order Bloch harmonics. Selective probing of forward- and backward-propagating modes as defined by their phase velocities enables direct quantification of topological robustness. Studying near-field propagation in controlled defects allows us to extract upper limits of topological protection in on-chip photonic systems in comparison with conventional PhC waveguides. We find that protected edge states are two orders of magnitude more robust than modes of conventional PhC waveguides. This direct experimental quantification of topological robustness comprises a crucial step toward the application of topologically protected guiding in integrated photonics, allowing for unprecedented error-free photonic quantum networks.

Highly stretchable conductive fabric using knitted cotton/lycra treated with polypyrrole/silver NPs composites post-treated with PEDOT:PSS

2021 ◽  
pp. 152808372110592
Author(s):  
Vahid Shakeri Siavashani ◽  
Gursoy Nevin ◽  
Majid Montazer ◽  
Pelin Altay
Keyword(s):  
Electrical Conductivity ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Morphological Observation ◽  
Wearable Electronics ◽  
Flexible Sensors ◽  
X Ray ◽  
Fabric Surface

Flexible sensors and wearable electronics have become important in recent years. A good conductive and flexible textile is needed to develop a commercial wearable device. Conductive polymers have generally been used with limitation in reducing the surface resistance to a certain amount. In this research, a method for fabricating a stretchable highly conductive cotton/lycra knitted fabric is introduced by treating the fabric with polypyrrole (PPy), silver nanoparticles (SNPs) composites, and post-treating with poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT:PSS). Polypyrrole and SNPs were in situ fabricated on the cotton/lycra fabric by consecutive redox reaction of silver nitrate and pyrrole and finally covered by PEDOT:PSS solution through dip-coating. The coated textile was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray mapping, and energy dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy confirmed PPy-SNPs (P-S) composites on the fabric surface. Fourier transform infrared spectroscopy results, X-ray mapping, EDAX, and XRD analysis also confirmed the P-S composites and PEDOT:PSS polymeric layer on the fabric. Morphological observation showed a layer of PEDOT:PSS on the P-S caused the higher connection of coating on textiles which resulted in the higher electrical conductivity (43 s/m). Also morphological observations showed penetration of the silver particles inside fibers which represented improving in attachment and stability of the coating on the fibers. Further, the electrical conductivity of PPy-SNPs-PEDOT:PSS coated textile increased under the tension. Hence, the stretchable and highly conductive knitted cotton/lycra fabric has potentiality to be used for fabricating the flexible sensors or wearable electronics.

scholarly journals Anisotropic excitation of surface plasmon polaritons on a metal film by a scattering-type scanning near-field microscope with a non-rotationally-symmetric probe tip

Nanophotonics ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 269-276 ◽  
Author(s):  
Frederik Walla ◽  
Matthias M. Wiecha ◽  
Nicolas Mecklenbeck ◽  
Sabri Beldi ◽  
Fritz Keilmann ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Surface Plasmon Polaritons ◽  
Metal Film ◽  
Near Infrared ◽  
Near Field ◽  
Optical Microscope ◽  
Anisotropic Surface ◽  
Surface Wave Propagation ◽  
Rotationally Symmetric ◽  
Plasmon Polaritons

AbstractWe investigated the excitation of surface plasmon polaritons on gold films with the metallized probe tip of a scattering-type scanning near-field optical microscope (s-SNOM). The emission of the polaritons from the tip, illuminated by near-infrared laser radiation, was found to be anisotropic and not circularly symmetric as expected on the basis of literature data. We furthermore identified an additional excitation channel via light that was reflected off the tip and excited the plasmon polaritons at the edge of the metal film. Our results, while obtained for a non-rotationally-symmetric type of probe tip and thus specific for this situation, indicate that when an s-SNOM is employed for the investigation of plasmonic structures, the unintentional excitation of surface waves and anisotropic surface wave propagation must be considered in order to correctly interpret the signatures of plasmon polariton generation and propagation.

Nonlinear nanoelectrodynamics of a Weyl metal

2021 ◽  
Vol 118 (48) ◽  
pp. e2116366118
Author(s):  
Yinming Shao ◽  
Ran Jing ◽  
Sang Hoon Chae ◽  
Chong Wang ◽  
Zhiyuan Sun ◽  
...  
Keyword(s):  
Electric Fields ◽  
Mirror Symmetry ◽  
Density Functional ◽  
Near Field ◽  
Surface States ◽  
Real Space ◽  
Resonance Structure ◽  
Nonlinear Conductivity ◽  
Weyl Semimetal ◽  
Photocurrent Spectroscopy

Chiral Weyl fermions with linear energy-momentum dispersion in the bulk accompanied by Fermi-arc states on the surfaces prompt a host of enticing optical effects. While new Weyl semimetal materials keep emerging, the available optical probes are limited. In particular, isolating bulk and surface electrodynamics in Weyl conductors remains a challenge. We devised an approach to the problem based on near-field photocurrent imaging at the nanoscale and applied this technique to a prototypical Weyl semimetal TaIrTe4. As a first step, we visualized nano-photocurrent patterns in real space and demonstrated their connection to bulk nonlinear conductivity tensors through extensive modeling augmented with density functional theory calculations. Notably, our nanoscale probe gives access to not only the in-plane but also the out-of-plane electric fields so that it is feasible to interrogate all allowed nonlinear tensors including those that remained dormant in conventional far-field optics. Surface- and bulk-related nonlinear contributions are distinguished through their “symmetry fingerprints” in the photocurrent maps. Robust photocurrents also appear at mirror-symmetry breaking edges of TaIrTe4 single crystals that we assign to nonlinear conductivity tensors forbidden in the bulk. Nano-photocurrent spectroscopy at the boundary reveals a strong resonance structure absent in the interior of the sample, providing evidence for elusive surface states.

scholarly journals Ultrafast nonlocal collective dynamics of Kane plasmon-polaritons in a narrow-gap semiconductor

2019 ◽  
Vol 5 (8) ◽  
pp. eaau9956 ◽  
Author(s):  
A. Charnukha ◽  
A. Sternbach ◽  
H. T. Stinson ◽  
R. Schlereth ◽  
C. Brüne ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Near Field ◽  
Three Dimensional ◽  
Large Momentum ◽  
Light Sources ◽  
New States ◽  
High Bandwidth ◽  
And Control ◽  
2D And 3D ◽  
Plasmon Polaritons

The observation of ultrarelativistic fermions in condensed-matter systems has uncovered a cornucopia of novel phenomenology as well as a potential for effective ultrafast light engineering of new states of matter. While the nonequilibrium properties of two- and three-dimensional (2D and 3D) hexagonal crystals have been studied extensively, our understanding of the photoinduced dynamics in 3D single-valley ultrarelativistic materials is, unexpectedly, lacking. Here, we use ultrafast scanning near-field optical spectroscopy to access and control nonequilibrium large-momentum plasmon-polaritons in thin films of a prototypical narrow-bandgap semiconductor Hg0.81Cd0.19Te. We demonstrate that these collective excitations exhibit distinctly nonclassical scaling with electron density characteristic of the ultrarelativistic Kane regime and experience ultrafast initial relaxation followed by a long-lived highly coherent state. Our observation and ultrafast control of Kane plasmon-polaritons in a semiconducting material using light sources in the standard telecommunications fiber-optics window open a new avenue toward high-bandwidth coherent information processing in next-generation plasmonic circuits.

scholarly journals Experimental demonstration of surface and bulk plasmon polaritons in hypergratings

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Kandammathe Valiyaveedu Sreekanth ◽  
Antonio De Luca ◽  
Giuseppe Strangi
Keyword(s):  
Experimental Demonstration ◽  
Bulk Plasmon ◽  
Plasmon Polaritons
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