Flow of free electrons or ions across a dielectric surface in vacuum

Author(s):  
M. J. Kofoid ◽  
V. H. Cleva
2021 ◽  
Vol 91 (12) ◽  
pp. 1916
Author(s):  
С.Г. Давыдов ◽  
А.Н. Долгов ◽  
А.А. Козлов ◽  
Р.Х. Якубов

The ionization of a rarefied gas in a short gap by a stream of short-wave radiation and fast electrons from the plasma of an auxiliary spark discharge along the dielectric surface is detected, sufficient to initiate an arc discharge in the gap. The density of the ionizing flow of particles and radiation determines the delay time of the switching gap in relation to the start of the auxiliary discharge. With an increase in the initial concentration of free electrons in the main discharge gap, the transition time to an arc discharge is reduced, due to the development of instabilities.


2019 ◽  
Vol 37 (4) ◽  
pp. 381-385
Author(s):  
Soni Sharma ◽  
A. Vijay

AbstractAn analytical formalism of laser absorption in a nanorod embedded dielectric surface has been developed. Nanorods lie in the plane of the dielectric, in the form of a planar array. A laser, impinged on them with an electric field perpendicular to the lengths of the nanorods, imparts oscillatory velocity to nanorod electrons. As the free electrons of a nanorod are displaced, a space charge field is developed in the nanorod that exerts restoration force on the electrons and their drift velocity shows a resonance at ${\rm \omega} = {\rm \omega} _{\rm p}/\sqrt 2 $, where ωp denotes the plasma frequency of free electrons inside the nanorod. It is inhibited by collisions and nanorod expansion. At the resonance, the electrons are efficiently heated by the laser and laser energy is strongly absorbed, resulting in significant reduction in laser transmissivity. The transmissivity decreases with laser intensity.


Author(s):  
C. Hayzelden ◽  
J. L. Batstone

Epitaxial reordering of amorphous Si(a-Si) on an underlying single-crystal substrate occurs well below the melt temperature by the process of solid phase epitaxial growth (SPEG). Growth of crystalline Si(c-Si) is known to be enhanced by the presence of small amounts of a metallic phase, presumably due to an interaction of the free electrons of the metal with the covalent Si bonds near the growing interface. Ion implantation of Ni was shown to lower the crystallization temperature of an a-Si thin film by approximately 200°C. Using in situ transmission electron microscopy (TEM), precipitates of NiSi2 formed within the a-Si film during annealing, were observed to migrate, leaving a trail of epitaxial c-Si. High resolution TEM revealed an epitaxial NiSi2/Si(l11) interface which was Type A. We discuss here the enhanced nucleation of c-Si and subsequent silicide-mediated SPEG of Ni-implanted a-Si.Thin films of a-Si, 950 Å thick, were deposited onto Si(100) wafers capped with 1000Å of a-SiO2. Ion implantation produced sharply peaked Ni concentrations of 4×l020 and 2×l021 ions cm−3, in the center of the films.


2018 ◽  
Vol 7 (7) ◽  
pp. 31-36
Author(s):  
Vyacheslav I. ASYUNIN ◽  
◽  
Sergei G. DAVYDOV ◽  
Alexander N. DOLGOV ◽  
Andrei V. KORNEYEV ◽  
...  

2021 ◽  
Vol 7 (11) ◽  
pp. eabe4270 ◽  
Author(s):  
A. Ben Hayun ◽  
O. Reinhardt ◽  
J. Nemirovsky ◽  
A. Karnieli ◽  
N. Rivera ◽  
...  

It is a long-standing goal to create light with unique quantum properties such as squeezing and entanglement. We propose the generation of quantum light using free-electron interactions, going beyond their already ubiquitous use in generating classical light. This concept is motivated by developments in electron microscopy, which recently demonstrated quantum free-electron interactions with light in photonic cavities. Such electron microscopes provide platforms for shaping quantum states of light through a judicious choice of the input light and electron states. Specifically, we show how electron energy combs implement photon displacement operations, creating displaced-Fock and displaced-squeezed states. We develop the theory for consecutive electron-cavity interactions with a common cavity and show how to generate any target Fock state. Looking forward, exploiting the degrees of freedom of electrons, light, and their interaction may achieve complete control over the quantum state of the generated light, leading to novel light statistics and correlations.


Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 861
Author(s):  
Minako Kubo ◽  
Minako Tachiki ◽  
Terumasa Mitogawa ◽  
Kota Saito ◽  
Ryota Saito ◽  
...  

Solution-cast coating films of perchlorate-doped oligo(3-methoxythiophene) exhibited a gold-like luster similar to that of metallic gold despite the involvement of no metals. However, the development mechanism of the luster remains ambiguous. To understand the mechanism, we performed scanning electron microscopic analysis, variable-angle spectral reflectance measurements, and ellipsometry measurements on ClO4−-doped oligo(3-methoxythiophene) cast film with a gold-like luster. The results revealed that the lustrous color of the film was not induced by the submicron-sized regular structures (structural color), nor by the high-density free electrons (reflective response based on Drude model), but by the large optical constants (refractive index and extinction coefficient) of the film, as speculated previously.


Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3303-3313 ◽  
Author(s):  
Wen Jun Ding ◽  
Jeremy Zhen Jie Lim ◽  
Hue Thi Bich Do ◽  
Xiao Xiong ◽  
Zackaria Mahfoud ◽  
...  

AbstractParticle simulation has been widely used in studying plasmas. The technique follows the motion of a large assembly of charged particles in their self-consistent electric and magnetic fields. Plasmons, collective oscillations of the free electrons in conducting media such as metals, are connected to plasmas by very similar physics, in particular, the notion of collective charge oscillations. In many cases of interest, plasmons are theoretically characterized by solving the classical Maxwell’s equations, where the electromagnetic responses can be described by bulk permittivity. That approach pays more attention to fields rather than motion of electrons. In this work, however, we apply the particle simulation method to model the kinetics of plasmons, by updating both particle position and momentum (Newton–Lorentz equation) and electromagnetic fields (Ampere and Faraday laws) that are connected by current. Particle simulation of plasmons can offer insights and information that supplement those gained by traditional experimental and theoretical approaches. Specifically, we present two case studies to show its capabilities of modeling single-electron excitation of plasmons, tracing instantaneous movements of electrons to elucidate the physical dynamics of plasmons, and revealing electron spill-out effects of ultrasmall nanoparticles approaching the quantum limit. These preliminary demonstrations open the door to realistic particle simulations of plasmons.


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