Modeling of Electrical Parameters of Thunderstorms Including Turbulent Effects

Radiophysics and Quantum Electronics - We study the effects of turbulence on the electrification of thunderclouds. Analytical estimates of the disturbances of electrical parameters (in particular,...     

Electromagnetic Effects on Plasma Resonance Cones

The electromagnetic modifications to the electrostatic theory of plasma resonance cones are presented for frequencies sufficiently high to allow the neglect of ion motion. The amplitude of the potential near the resonance cone is studied numerically and analytically when electromagnetic effects can be considered to be a small correction. The most important effects are a reduction in amplitude and an angular shift of the main peak and interference structure. The conditions under which these effects are important are derived.     

Effects of Spatial Nonlocality versus Nonlocal Causality for Bound Electrons in External Fields

Using numerically exact solution of the time-dependent Schrödinger equation together with time-dependent quantum Monte Carlo (TDQMC) calculations, here we compare the effects of spatial nonlocality versus nonlocal causality for the ground state and for real-time evolution of two entangled electrons in parabolic potential in one spatial dimension. It was found that the spatial entanglement quantified by the linear quantum entropy is predicted with good accuracy using the spatial nonlocality, parameterized naturally within the TDQMC approach. At the same time, the nonlocal causality predicted by the exact solution leads to only small oscillations in the quantum trajectories which belong to the idler electron as the driven electron is subjected to a strong high frequency electric field, without interaction between the electrons.     

Nonlocal transformation optics

We show that the powerful framework of transformation optics may be exploited for engineering the nonlocal response of artificial electromagnetic materials. Relying on the form-invariant properties of coordinate-transformed Maxwell's equations in the spectral domain, we derive the general constitutive "blueprints" of transformation media yielding prescribed nonlocal field-manipulation effects and provide a physically incisive and powerful geometrical interpretation in terms of deformation of the equifrequency contours. In order to illustrate the potentials of our approach, we present an example of application to a wave-splitting refraction scenario, which may be implemented via a simple class of artificial materials. Our results provide a systematic and versatile framework which may open intriguing venues in dispersion engineering of artificial materials.     

Transient Diffusion in Triangular Cylinders

A heated triangular cylinder is suddenly cooled in a constant temperature bath. The transient heat conduction problem is transformed to the Helmholtz equation related to the vibration of membranes. Using the membrane analogy, exact analytic solutions for the transient heat conduction problem for three triangular cross sections are found.     

Nonlocal heat transfer in nanostructures

Kinetics of electrons in a degenerate conductor heated up by absorption of a high-frequency field localized in a region of about hundred nanometers has been studied. A new law for nonlocal electron thermal flux has been predicted.     

Nonlocal feedback in nonlinear systems

A shifted or misaligned feedback loop gives rise to a two-point nonlocality that is the spatial analog of a temporal delay. Important consequences of this nonlocal coupling have been found both in diffusive and in diffractive systems, and include convective instabilities, independent tuning of phase and group velocities, as well as amplification, chirping and even splitting of localized perturbations. Analytical predictions about these nonlocal systems as well as their spatio-temporal dynamics are discussed in one and two transverse dimensions and in presence of noise.     

Nonlocal Ginzburg-Landau Equations

Real time Gor'kov equations and the accompanying electric current expression in terms of the retarded Green's functions are established at finite temperatures with the aid of the Closed-Time-Path-Green's-Function formalism. The fluctuation-dissipation theorem then helps us to obtain nonlocal G-L equations near T_c which reduces to the conventional G-L equations in the local limit. The kernel containing nonlocal effects in our equations has an asymptotic behavior k^-2 for k → ∞ and is, therefore, quite different from the BCS kernel. This novel kernel leads naturally to reversal of the magnetic field in the neighborhood of a vortex in type Ⅱ/1 superconductors.     

Nonlocal surface-wave solitons

We demonstrate, experimentally and theoretically, surface-wave solitons occurring at the interface between a dielectric medium (air) and a nonlinear material with a very long-range nonlocal response. These surface solitons are always attracted toward the surface, and unlike their Kerr-like counterparts, they do not exhibit a power threshold.     

Microscopic Many-Body Effects on Intersubband Resonance in Quantum Well

Considering the Coulomb many-body interactions, we investigate the intersubband optical processes of the quantum well by using the semiconductor Bloch equations. We calculate the evolution of intersubband absorption spectral line shape as a function of lattice temperature and electron density. It is found that the coupling of intersubband plasmons can reduce and red-shift the lower energy resonance, simultaneously enhance and blue-shift the higher energy resonance. The dependence of cascading resonances on temperature and electron density is also discussed.     

多端口石墨烯系统中的非局域电阻

非局域测量方法由于其能够间接探测某些难以直接俘获的非平庸物理机理,近年来已逐渐成为凝聚态物理的研究热点之一.最近的实验在H形多端口石墨烯样品中发现了巨大的非局域电阻信号.在排除了经典欧姆、边缘态等可能的输运形式后,人们倾向于认为这类非局域电阻是由多端石墨烯系统中存在的自旋霍尔效益或谷霍尔效应所导致.借助于非平衡格林函数输运计算,目前的理论可以在同样的多端石墨烯体系中得到部分与实验符合较好的数值模拟结果.针对实验中发现的某些难以理解的、甚至与经典理论相矛盾的非局域电阻性质,例如非局域电阻相比局域电阻在偏离电中性点时的迅速衰减、出现在能隙中的非局域电阻峰值等,目前的理论研究取得了一定的进展,但对这些奇异现象的理解仍存在较大的争议.本综述详细回顾了多端口石墨烯体系中非局域电阻的相关实验,并针对性地介绍与之配套的理论进展及对未来研究的展望.     

Nonlocal action in the induction motor

It is pointed out that local field-contact action depends entirely on field-energy momentum transfer to matter, orvice versa. Contact with stationary electromagnetic energy does not produce forces. With this in mind, the paper examines the electrodynamic operation of the common induction motor and concludes that the motor is not, and could not be, driven by local field-contact action.     

Nonlocal effects in black body radiation

Nonlocal electrodynamics is a formalism developed to include nonlocal effects in the measurement process in order to account for the impossibility of instantaneous measurement of physical fields. This theory modifies Maxwell's electrodynamics by eliminating the hypothesis of locality that assumes an accelerated observer simultaneously equivalent to a comoving inertial frame of reference. In this scenario, the transformation between an inertial and accelerated observer is generalized which affects the properties of physical fields. In particular, we analyze how an uniformly accelerated observer perceives a homogeneous and isotropic black body radiation. We show that all nonlocal effects are transient and most relevant in the first period of acceleration.

     

Nonlocal nucleon-nucleon interaction JISP

The J-matrix inverse scattering formalism is described and a new type of nucleon-nucleon interaction JISP is constructed within its framework. Interaction for each partial NN scattering is represented by a small matrix in the oscillator basis, which allows its direct use in multiparticle shell-model calculations and in calculations within the resonating group approximation. The JISP reproduces np scattering data and deuteron characteristics with an accuracy of modern realistic NN potentials (x ²/datum = 1.05). The generalization of this interaction which takes into account violation of charge independence of nucleon-nucleon forces is proposed and pp scattering phases calculated with this new charge-dependent interaction CD-JISP are discussed.