scholarly journals Coherent interaction between free electrons and a photonic cavity

Nature ◽  
2020 ◽  
Vol 582 (7810) ◽  
pp. 50-54 ◽  
Author(s):  
Kangpeng Wang ◽  
Raphael Dahan ◽  
Michael Shentcis ◽  
Yaron Kauffmann ◽  
Adi Ben Hayun ◽  
...  
Keyword(s):  
Free Electrons ◽  
Coherent Interaction

Dynamic studies of silicide-mediated crystallization of amorphous silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1352-1353
Author(s):  
C. Hayzelden ◽  
J. L. Batstone
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Metallic Phase ◽  
Single Crystal Substrate ◽  
Free Electrons ◽  
Melt Temperature ◽  
Transmission Electron ◽  
Crystal Substrate ◽  
High Resolution Tem

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.

scholarly journals Shaping quantum photonic states using free electrons

2021 ◽  
Vol 7 (11) ◽  
pp. eabe4270 ◽  
Author(s):  
A. Ben Hayun ◽  
O. Reinhardt ◽  
J. Nemirovsky ◽  
A. Karnieli ◽  
N. Rivera ◽  
...  
Keyword(s):  
Free Electron ◽  
Degrees Of Freedom ◽  
Free Electrons ◽  
Complete Control ◽  
Fock State ◽  
Judicious Choice ◽  
Electron Microscopes ◽  
Photonic States ◽  
Photonic Cavities ◽  
Electron Interactions

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.

scholarly journals Mechanistic Study on Gold-Like Luster Development of Solution-Cast Oligo(3-methoxythiophene) Film

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 861
Author(s):  
Minako Kubo ◽  
Minako Tachiki ◽  
Terumasa Mitogawa ◽  
Kota Saito ◽  
Ryota Saito ◽  
...  
Keyword(s):  
Microscopic Analysis ◽  
Mechanistic Study ◽  
Free Electrons ◽  
Coating Films ◽  
Electron Microscopic ◽  
Regular Structures ◽  
Scanning Electron Microscopic ◽  
Solution Cast ◽  
Scanning Electron Microscopic Analysis ◽  
Reflectance Measurements

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.

scholarly journals Particle simulation of plasmons

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 ◽  
...  
Keyword(s):  
Simulation Method ◽  
Electron Excitation ◽  
Particle Simulation ◽  
Quantum Limit ◽  
Free Electrons ◽  
Theoretical Approaches ◽  
Electromagnetic Responses ◽  
Electric And Magnetic Fields ◽  
Particle Simulations ◽  
Collective Oscillations

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.

Is Thermal and Light-Induced Annealing of Met Astable Defects in a-Si:H Driven by Electrons?

1995 ◽  
Vol 377 ◽  
Author(s):  
Helena Gleskova ◽  
S. Wagner
Keyword(s):  
Electrical Conductivity ◽  
Light Intensity ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Free Electrons ◽  
Free Electron Density ◽  
Independent Variables ◽  
The Third ◽  
Defect Annealing ◽  
Hydrogenated Amorphous

ABSTRACTWe report results of a search for a unifying rate law for the annealing of metastable defects in hydrogenated amorphous silicon (a-Si:H). We tested the hypothesis that defect-annealing by both heating or illumination is driven by the density of free electrons. This hypothesis is formulated via the rate equation - dN/dt = A nα N f (T), where N is the defect density, t the time, A a constant, n the free electron density, and f (T) a function of temperature derived from a distribution of annealing energies. The model fits two sets of data, with light-intensity and electrical conductivity as the independent variables, reasonably well, with a ranging from 0.39 to 0.76, but not the third set, where we varied the temperature.

scholarly journals Optical gating and streaking of free electrons with sub-optical cycle precision

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
M. Kozák ◽  
J. McNeur ◽  
K. J. Leedle ◽  
H. Deng ◽  
N. Schönenberger ◽  
...  
Keyword(s):  
Free Electrons ◽  
Optical Gating ◽  
Optical Cycle

scholarly journals Effects of Thermal Annealing on the Properties of Zirconium-Doped MgxZn1−XO Films Obtained through Radio-Frequency Magnetron Sputtering

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 373
Author(s):  
Wen-Yen Lin ◽  
Feng-Tsun Chien ◽  
Hsien-Chin Chiu ◽  
Jinn-Kong Sheu ◽  
Kuang-Po Hsueh
Keyword(s):  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Photoelectron Spectroscopy ◽  
Annealing Temperature ◽  
Radio Frequency Magnetron ◽  
Radio Frequency Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Free Electrons ◽  
X Ray ◽  
Mg Content

Zirconium-doped MgxZn1−xO (Zr-doped MZO) mixed-oxide films were investigated, and the temperature sensitivity of their electric and optical properties was characterized. Zr-doped MZO films were deposited through radio-frequency magnetron sputtering using a 4-inch ZnO/MgO/ZrO2 (75/20/5 wt%) target. Hall measurement, X-ray diffraction (XRD), transmittance, and X-ray photoelectron spectroscopy (XPS) data were obtained. The lowest sheet resistance, highest mobility, and highest concentration were 1.30 × 103 Ω/sq, 4.46 cm2/Vs, and 7.28 × 1019 cm−3, respectively. The XRD spectra of the as-grown and annealed Zr-doped MZO films contained MgxZn1−xO(002) and ZrO2(200) coupled with Mg(OH)2(101) at 34.49°, 34.88°, and 38.017°, respectively. The intensity of the XRD peak near 34.88° decreased with temperature because the films that segregated Zr4+ from ZrO2(200) increased. The absorption edges of the films were at approximately 348 nm under 80% transmittance because of the Mg content. XPS revealed that the amount of Zr4+ increased with the annealing temperature. Zr is a potentially promising double donor, providing up to two extra free electrons per ion when used in place of Zn2+.

scholarly journals Cryogenic Exfoliation of 2D Stanene Nanosheets for Cancer Theranostics

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jiang Ouyang ◽  
Ling Zhang ◽  
Leijiao Li ◽  
Wei Chen ◽  
Zhongmin Tang ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Density Functional ◽  
Biomedical Application ◽  
Density Functional Theory Calculations ◽  
Free Electrons ◽  
Functional Theory ◽  
New Approach ◽  
New Type ◽  
Average Size ◽  
Cancer Theranostics

Abstract Stanene (Sn)-based materials have been extensively applied in industrial production and daily life, but their potential biomedical application remains largely unexplored, which is due to the absence of the appropriate and effective methods for fabricating Sn-based biomaterials. Herein, we explored a new approach combining cryogenic exfoliation and liquid-phase exfoliation to successfully manufacture two-dimensional (2D) Sn nanosheets (SnNSs). The obtained SnNSs exhibited a typical sheet-like structure with an average size of ~ 100 nm and a thickness of ~ 5.1 nm. After PEGylation, the resulting PEGylated SnNSs (SnNSs@PEG) exhibited good stability, superior biocompatibility, and excellent photothermal performance, which could serve as robust photothermal agents for multi-modal imaging (fluorescence/photoacoustic/photothermal imaging)-guided photothermal elimination of cancer. Furthermore, we also used first-principles density functional theory calculations to investigate the photothermal mechanism of SnNSs, revealing that the free electrons in upper and lower layers of SnNSs contribute to the conversion of the photo to thermal. This work not only introduces a new approach to fabricate 2D SnNSs but also establishes the SnNSs-based nanomedicines for photonic cancer theranostics. This new type of SnNSs with great potential in the field of nanomedicines may spur a wave of developing Sn-based biological materials to benefit biomedical applications.

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