Article
Astronomy & Astrophysics
Alfred Mallet, Jonathan Squire, Benjamin D. G. Chandran, Trevor Bowen, Stuart D. Bale
Summary: This study examines the dynamics of large-amplitude Alfven waves in the expanding solar wind, making predictions about the occurrence and characteristics of switchbacks observed by the Parker Solar Probe. The expansion of plasma generates compressive components in the wave's evolution, affecting the magnetic field strength and gradient of switchbacks. The findings suggest that observed switchbacks may result from the nonlinear evolution of initially small-amplitude Alfven waves.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physics, Fluids & Plasmas
Haomin Sun, Jian Chen, Igor D. Kaganovich, Alexander Khrabrov, Dmytro Sydorenko
Summary: This paper extensively studies the collective processes of a mono-energetic electron beam propagating through a cold plasma. It identifies four different physical regimes of the beam-plasma interaction and discovers a new regime called electron modulational instability (EMI). In this EMI regime, the interaction occurs in an intermittent process with strong scattering of beam electrons and broadening of the Langmuir wave spectrum.
Article
Chemistry, Multidisciplinary
Yocefu Hattori, Jie Meng, Kaibo Zheng, Ageo Meier de Andrade, Jolla Kullgren, Peter Broqvist, Peter Nordlander, Jacinto Sa
Summary: By adjusting the operating temperature, the hot electron generation and transfer in plasmonic semiconductor materials can be optimized, contrasting with photodriven processes in nonplasmonic systems. This effect appears to be related to an enhancement in hot carrier generation due to phonon coupling. This discovery provides a new strategy for the optimization of photodriven energy production and chemical synthesis.
Article
Mechanics
E. Parente, J-Ch Robinet, P. De Palma, S. Cherubini
Summary: Recently, the origin and growth of turbulent bands in shear flows have been investigated. Streaks and their inflectional instability play a significant role in the process. Linear and nonlinear energy optimisations reveal the mechanisms allowing the creation of a turbulent band in a tilted domain. Linear optimal perturbation generates oblique streaks, inducing turbulence in the whole domain. Spatially localised perturbations lead to the generation of a localised turbulent band.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Astronomy & Astrophysics
F. S. Mozer, J. W. Bonnell, E. L. M. Hanson, L. C. Gasque, I. Y. Vasko
Summary: Nonlinear ion-acoustic waves, ion holes, and electron holes have been observed on the Parker Solar Probe at a heliocentric distance of 35 solar radii. These structures contain electric field spikes of several mV m(-1) and are observed inside or at boundaries of switchbacks in the background magnetic field, indicating electrostatic instabilities occurring to thermalize electron and ion beams.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physics, Fluids & Plasmas
S. H. Cao, C. Ren
Summary: A series of simulations using particle-in-cell method reveals different paths of laser-plasma instability evolution in OMEGA-scale implosions, depending on the initial electron temperature. At low temperatures, two-plasmon decay dominates, while at high temperatures, stimulated Raman scattering becomes the dominant mode. However, regardless of temperature, two-plasmon decay still dominates in the steady state. The simulations also provide a scaling law for hot electron generation, which, combined with laser/plasma conditions, can predict their generation in implosions.
PHYSICS OF PLASMAS
(2023)
Article
Engineering, Aerospace
Mehul Chakraborty, Vipin K. Yadav, Rajneesh Kumar
Summary: The generation of Two-stream Instability (TSI) in the lunar ionosphere is analytically studied. TSI is a small perturbation in the electron plasma density, resulting in the growth of an electric field facilitated by the electron plasma in the background. TSI occurs in the lunar ionosphere when the solar wind interacts unhindered with the tenuous lunar electron plasma in the surface bound exosphere. This study investigates the conditions and factors contributing to the formation and growth of TSI, and presents the evolution of plasma TSI with the passage of time through Particle-In-Cell simulations.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Physics, Multidisciplinary
Mostafa M. A. Khater, A. A. Mousa, M. A. El-Shorbagy, Raghda A. M. Attia
Summary: In this manuscript, the computational solutions of the nonlinear Klein-Gordon-Zakharov (KGZ) model are scrutinized through a new generalized analytical scheme, demonstrating various physical and dynamical attitudes. The capabilities for managing a class of nonlinear evolution equations of the new generalized method are assessed, and the stability property of the obtained solutions is checked using the characteristics of the Hamiltonian system.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Nanoscience & Nanotechnology
Ly Thi Minh Huynh, Seokheon Kim, Sangwoon Yoon
Summary: This study compares the efficiency of hot carrier generation between gold and silver nanoparticles, as well as between spherical and cubic gold nanoparticles. The results show that silver nanoparticles are more effective in generating hot carriers than gold nanoparticles, and cubic gold nanoparticles have a slightly better hot carrier generation than spherical ones. These findings are important for the design of highly efficient plasmonic catalysts and photovoltaic materials.
Review
Chemistry, Multidisciplinary
Andrew J. Bagnall, Sagar Ganguli, Alina Sekretareva
Summary: This review focuses on the mechanisms behind photocurrents observed in plasmon-enhanced electrocatalysis (PEEC) and critically evaluates alternative sources of current enhancement. Guidelines for experimentalists to distinguish between different enhancement mechanisms in PEEC are presented.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Physics, Fluids & Plasmas
D. S. Agafontsev, S. Randoux, P. Suret
Summary: In the framework of the focusing one-dimensional nonlinear Schrödinger equation, integrable turbulence developing from partially coherent waves are studied numerically. It is found that narrower initial spectra lead to higher frequencies of rogue waves in the turbulence. In the extreme case of very narrow initial spectrum, a quasi-steady state is entered with slow statistical evolution before reaching asymptotic stationary state.
Article
Mechanics
Tianyi Li, Lian Shen
Summary: The dynamics of wind-generated water waves in the principal stage of the Phillips theory is investigated using numerical and analytical approaches. The study confirms the existence of a principal stage and proposes a random sweeping turbulence pressure-wave interaction model to describe wave generation.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Nanoscience & Nanotechnology
Katarzyna Kluczyk-Korch, Tomasz. J. J. Antosiewicz
Summary: In strongly coupled light matter systems, the electronic energy levels and local electromagnetic field modes are intricately linked. The hybridization of these states creates new relaxation pathways, which are particularly important for plasmon decay into hot carriers. By using first principles calculations, we investigate the impact of the coupling strength between a plasmonic resonator and a molecule on hot carrier generation. Our atomistic approach enables the capture of changes in the electronic structure of the system. We find that hot carriers preferentially occur at excitation frequencies matching the new polaritonic resonances, and their energy distribution deviates significantly from that of the non-interacting system. This suggests the existence of new plasmon decay paths due to the appearance of hybridized nanoparticle-molecule states. We also observe direct electron transfer between the plasmonic nanoparticle and the molecule. Therefore, we can conclude that strong interaction between plasmonic nanostructures and molecules allows for manipulation of the energy distribution of generated hot carriers and opens up possibilities for charge transfer in the system.
Article
Physics, Fluids & Plasmas
Erik Gengel, Eyal Heifetz
Summary: This study is a direct follow-up to the previous paper by Heifetz and Guha, exploring a minimal nonlinear dynamical system that describes a linearized two-dimensional shear instability. By adding the effect of mutual interaction between the waves and the mean flow, the study reveals oscillatory Hamiltonian dynamics with phase slipping and finite-size wave amplitude oscillations. It further demonstrates that wave-mean flow dynamics resulting from unstable normal modes in the linearized stage exhibit oscillations around an antiphased neutral configuration where the waves hinder each other's counterpropagation rate. The study also discusses the connection between the dynamics observed and familiar models of phase oscillators.
Article
Physics, Multidisciplinary
Tianyi Li, Lian Shen
Summary: This study combines theoretical and computational methods to investigate the initial impact of turbulent wind on a calm water surface and analyzes the process of wind-wave generation based on Phillips theory. The study reveals that the wave energy grows following a quartic law during the early stages of wave generation and provides numerical evidence of the resonance mechanism, which plays a crucial role in the heterogeneous distribution of wave energy in the spectral space.
COMMUNICATIONS PHYSICS
(2023)