scholarly journals Spontaneous and stimulated electron–photon interactions in nanoscale plasmonic near fields

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Matthias Liebtrau ◽  
Murat Sivis ◽  
Armin Feist ◽  
Hugo Lourenço-Martins ◽  
Nicolas Pazos-Pérez ◽  
...  
Keyword(s):  
Quantum Information Processing ◽  
Near Field ◽  
Interaction Strength ◽  
Electron Velocity ◽  
Localized Surface Plasmon ◽  
Electron Trajectory ◽  
Field Electron Microscopy ◽  
Electron Photon ◽  
Photon Interactions ◽  
Time And Energy

AbstractThe interplay between free electrons, light, and matter offers unique prospects for space, time, and energy resolved optical material characterization, structured light generation, and quantum information processing. Here, we study the nanoscale features of spontaneous and stimulated electron–photon interactions mediated by localized surface plasmon resonances at the tips of a gold nanostar using electron energy-loss spectroscopy (EELS), cathodoluminescence spectroscopy (CL), and photon-induced near-field electron microscopy (PINEM). Supported by numerical electromagnetic boundary-element method (BEM) calculations, we show that the different coupling mechanisms probed by EELS, CL, and PINEM feature the same spatial dependence on the electric field distribution of the tip modes. However, the electron–photon interaction strength is found to vary with the incident electron velocity, as determined by the spatial Fourier transform of the electric near-field component parallel to the electron trajectory. For the tightly confined plasmonic tip resonances, our calculations suggest an optimum coupling velocity at electron energies as low as a few keV. Our results are discussed in the context of more complex geometries supporting multiple modes with spatial and spectral overlap. We provide fundamental insights into spontaneous and stimulated electron-light-matter interactions with key implications for research on (quantum) coherent optical phenomena at the nanoscale.

scholarly journals All-dielectric chiral-field-enhanced Raman optical activity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ting-Hui Xiao ◽  
Zhenzhou Cheng ◽  
Zhenyi Luo ◽  
Akihiro Isozaki ◽  
Kotaro Hiramatsu ◽  
...  
Keyword(s):  
Optical Activity ◽  
Metallic Nanoparticles ◽  
Near Field ◽  
Localized Surface Plasmon ◽  
Chiral Field ◽  
Resonance Spectroscopy ◽  
Conformational Structure ◽  
Dark Mode ◽  
Spontaneous Raman Scattering ◽  
Raman Optical Activity

AbstractRaman optical activity (ROA) is effective for studying the conformational structure and behavior of chiral molecules in aqueous solutions and is advantageous over X-ray crystallography and nuclear magnetic resonance spectroscopy in sample preparation and cost performance. However, ROA signals are inherently minuscule; 3–5 orders of magnitude weaker than spontaneous Raman scattering due to the weak chiral light–matter interaction. Localized surface plasmon resonance on metallic nanoparticles has been employed to enhance ROA signals, but suffers from detrimental spectral artifacts due to its photothermal heat generation and inability to efficiently transfer and enhance optical chirality from the far field to the near field. Here we demonstrate all-dielectric chiral-field-enhanced ROA by devising a silicon nanodisk array and exploiting its dark mode to overcome these limitations. Specifically, we use it with pairs of chemical and biological enantiomers to show >100x enhanced chiral light–molecule interaction with negligible artifacts for ROA measurements.

scholarly journals Novel droplet near-field transducer for heat-assisted magnetic recording

Nanophotonics ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 503-510 ◽  
Author(s):  
Jacek Gosciniak ◽  
Marcus Mooney ◽  
Mark Gubbins ◽  
Brian Corbett
Keyword(s):  
Surface Plasmon ◽  
Magnetic Recording ◽  
Near Field ◽  
Metal Structure ◽  
Spot Size ◽  
Impedance Match ◽  
Localized Surface Plasmon ◽  
Heat Assisted Magnetic Recording ◽  
Localized Surface Plasmon Resonances ◽  
High Degree

AbstractTwo main ingredients of plasmonics are surface plasmon polaritons (SPP) and localized surface plasmon resonances (LSPR) as they provide a high degree of concentration of electromagnetic fields in the vicinity of metal surfaces, which is well beyond that allowed by the diffraction limit of optics. Those properties have been used in the new technique of heat assisted magnetic recording (HAMR) to overcome an existing limit of conventional magnetic recording by utilizing a near-field transducer (NFT). The NFT designs are based on excitation of surface plasmons on a metal structure, which re-radiate with a subdiffraction limited light spot confined in the near field. In this paper, we propose a novel “droplet”-shaped NFT, which takes full advantage of a recenltly proposed Mach–Zehnder Interferometer (MZI), a coupling arrangement that allows optimal coupling of light to the transducer. The droplet design ensures better impedance match with the recording media and, consequently, better coupling of power. The droplet design results in very high enhancement of the electric field and allows the confinement of light in a spot size much smaller than the present stateof- the-art lollipop transducer.

Localized surface plasmon resonance shift and its application in scanning near-field optical microscopy

2021 ◽  
Author(s):  
Jiawei Zhang ◽  
Gitanjali Kolhatkar ◽  
Andreas Ruediger
Keyword(s):  
Raman Spectroscopy ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Near Field ◽  
Localized Surface Plasmon ◽  
Resonance Shift ◽  
Raman Modes ◽  
Tip Enhanced Raman Spectroscopy

The localized surface plasmon resonance (LSPR) position in tip-enhanced Raman spectroscopy (TERS) is of great importance to the understanding and interpretation of the relative intensity of different enhanced Raman modes....

scholarly journals Exact eigenstates of a nanometric paraboloidal emitter and field emission quantities

2018 ◽  
Vol 474 (2214) ◽  
pp. 20170692 ◽  
Author(s):  
A. Chatziafratis ◽  
G. Fikioris ◽  
J. P. Xanthakis
Keyword(s):  
Schrödinger Equation ◽  
Field Emission ◽  
Schrodinger Equation ◽  
Near Field ◽  
Plane Waves ◽  
Spot Size ◽  
Emission Angle ◽  
Electron Velocity ◽  
Cartesian Geometry ◽  
Tip Radius

The progress in field emission theory from its initial Fowler–Nordheim form is centred on the transmission coefficient. For the supply (of electrons) function one still uses the constant value due to a supply of plane-waves states. However, for emitting tips of apex radius of 1–5 nm this is highly questionable. To address this issue, we have solved the Schrödinger equation in a sharp paraboloidally shaped quantum box. The Schrödinger equation is separable in the rotationally parabolic coordinate system and we hence obtain the exact eigenstates of the system. Significant differences from the usual Cartesian geometry are obtained. (1) Both the normally incident and parallel electron fluxes are functions of the angle to the emitter axis and affect the emission angle. (2) The WKB approximation fails for this system. (3) The eigenfunctions of the nanoemitter form a continuum only in one dimension while complete discretization occurs in the other two directions. (4) The parallel electron velocity vanishes at the apex which may explain the recent spot-size measurements in near-field scanning electron microscopy. (5) Competing effects are found as the tip radius decreases to 1 nm: The electric field increases but the total supply function decreases so that possibly an optimum radius exists.

scholarly journals A single-photon switch and transistor enabled by a solid-state quantum memory

Science ◽  
2018 ◽  
Vol 361 (6397) ◽  
pp. 57-60 ◽  
Author(s):  
Shuo Sun ◽  
Hyochul Kim ◽  
Zhouchen Luo ◽  
Glenn S. Solomon ◽  
Edo Waks
Keyword(s):  
Solid State ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Internal State ◽  
Optical Signal ◽  
Quantum Memory ◽  
Strong Interactions ◽  
Strongly Coupled ◽  
Spin Qubit ◽  
Photon Interactions

Single-photon switches and transistors generate strong photon-photon interactions that are essential for quantum circuits and networks. However, the deterministic control of an optical signal with a single photon requires strong interactions with a quantum memory, which has been challenging to achieve in a solid-state platform. We demonstrate a single-photon switch and transistor enabled by a solid-state quantum memory. Our device consists of a semiconductor spin qubit strongly coupled to a nanophotonic cavity. The spin qubit enables a single 63-picosecond gate photon to switch a signal field containing up to an average of 27.7 photons before the internal state of the device resets. Our results show that semiconductor nanophotonic devices can produce strong and controlled photon-photon interactions that could enable high-bandwidth photonic quantum information processing.

scholarly journals Quasi-3D Plasmonic Nanowell Array for Molecular Enrichment and SERS-Based Detection

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 939
Author(s):  
Sunho Kim ◽  
Chaewon Mun ◽  
Dae-Geun Choi ◽  
Ho Sang Jung ◽  
Dong-Ho Kim ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Molecular Detection ◽  
Near Field ◽  
Field Enhancement ◽  
Triple Line ◽  
Surface Enhanced Raman Spectroscopy ◽  
High Density ◽  
Localized Surface Plasmon ◽  
Au Nps ◽  
Relative Standard

We report on a quasi-three-dimensional (3D) plasmonic nanowell array with high structural uniformity for molecular detection. The quasi-3D plasmonic nanowell array was composed of periodic hexagonal Au nanowells whose surface is densely covered with gold nanoparticles (Au NPs), separated by an ultrathin dielectric interlayer. The uniform array of the Au nanowells was fabricated by nanoimprint lithography and deposition of Au thin film. A self-assembled monolayer (SAM) of perfluorodecanethiol (PFDT) was coated on the Au surface, on which Au was further deposited. Interestingly, the PFDT-coated Au nanowells were fully covered with Au NPs with an ultra-high density of 375 μm−2 rather than a smooth film due to the anti-wetting property of the low-energy surface. The plasmonic nanogaps formed among the high-density Au NPs led to a strong near-field enhancement via coupled localized surface plasmon resonance and produced a uniform surface-enhanced Raman spectroscopy (SERS) response with a small relative standard deviation of 5.3%. Importantly, the highly uniform nanostructure, featured by the nanoimprint lithography and 3D growth of densely-packed Au NPs, minimizes the spatial variation of Raman intensity, potentially providing quantitative analysis. Moreover, analyte molecules were highly concentrated and selectively deposited in nanowells when a water droplet containing the analyte was evaporated on the plasmonic substrate. The analyte formed a relatively thick overcoat in the nanowells near the triple line due to the coffee-ring effects. Combining 3D plasmonic nanowell substrates with molecular enrichments, highly sensitive detection of lactic acid was demonstrated. Given its combination of high sensitivity and signal uniformity, the quasi-3D plasmonic nanowell substrate is expected to provide a superior molecular detection platform for biosensing applications.

scholarly journals Self-Organized Conductive Gratings of Au Nanostripe Dimers Enable Tunable Plasmonic Activity

2020 ◽  
Vol 10 (4) ◽  
pp. 1301
Author(s):  
Maria Caterina Giordano ◽  
Matteo Barelli ◽  
Giuseppe Della Valle ◽  
Francesco Buatier de Mongeot
Keyword(s):  
High Efficiency ◽  
Ion Beam ◽  
Near Field ◽  
Cost Effective ◽  
Localized Surface Plasmon ◽  
Large Area ◽  
Field Amplification ◽  
Self Organized ◽  
Broadband Spectrum ◽  
Out Of Plane

Plasmonic metasurfaces based on quasi-one-dimensional (1D) nanostripe arrays are homogeneously prepared over large-area substrates (cm2), exploiting a novel self-organized nanofabrication method. Glass templates are nanopatterned by ion beam-induced anisotropic nanoscale wrinkling, enabling the maskless confinement of quasi-1D arrays of out-of-plane tilted gold nanostripes, behaving as transparent wire-grid polarizer nanoelectrodes. These templates enable the dichroic excitation of localized surface plasmon resonances, easily tunable over a broadband spectrum from the visible to the near- and mid-infrared, by tailoring the nanostripes’ shape and/or changing the illumination conditions. The controlled self-organized method allows the engineering of the nanoantennas’ morphology in the form of Au-SiO2-Au nanostripe dimers, which show hybridized plasmonic resonances with enhanced tunability. Under this condition, superior near-field amplification is achievable for the excitation of the hybridized magnetic dipole mode, as pointed out by numerical simulations. The high efficiency of these plasmonic nanoantennas, combined with the controlled tuning of the resonant response, opens a variety of applications for these cost-effective templates, ranging from biosensing and optical spectroscopies to high-resolution molecular imaging and nonlinear optics.

scholarly journals Double-resonant enhancement of third-harmonic generation in graphene nanostructures

2017 ◽  
Vol 375 (2090) ◽  
pp. 20160313 ◽  
Author(s):  
Jian Wei You ◽  
Jie You ◽  
Martin Weismann ◽  
Nicolae C. Panoiu
Keyword(s):  
Harmonic Generation ◽  
Spectral Response ◽  
Near Field ◽  
Field Enhancement ◽  
Third Harmonic Generation ◽  
Resonance Wavelength ◽  
Localized Surface Plasmon ◽  
Third Harmonic ◽  
New Horizons ◽  
Geometry Dependence

Intriguing and unusual physical properties of graphene offer remarkable potential for advanced, photonics-related technological applications, particularly in the area of nonlinear optics at the deep-subwavelength scale. In this study, we use a recently developed numerical method to illustrate an efficient mechanism that can lead to orders of magnitude enhancement of the third-harmonic generation in graphene diffraction gratings. In particular, we demonstrate that by taking advantage of the geometry dependence of the resonance wavelength of localized surface-plasmon polaritons of graphene ribbons and discs one can engineer the spectral response of graphene gratings so that strong plasmonic resonances exist at both the fundamental frequency and third-harmonic (TH). As a result of this double-resonant mechanism for optical near-field enhancement, the intensity of the TH can be increased by more than six orders of magnitude. This article is part of the themed issue ‘New horizons for nanophotonics’.

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