相关论文: A New Approximation Of ECM Frequencies
Electromagnetic (EM) wave scattering by many parallel infinite cylinders is studied asymptotically as a tends to 0, where a is the radius of the cylinders. It is assumed that the centres of the cylinders are distributed so that their…
Absorption is usually expected to be detrimental to quantum coherence effects. However, the situation for complex absorption spectra has been little studied yet. We consider the resonance fluorescence of excitons in a semiconductor quantum…
The amplification of acoustic phonons in a superlattice in the presence of an electric field $E =E_0 + E_1 cos(\omega t)$ has been investigated theoretically and numerically by computational methods. The calculation is done in the…
Nonlinear forces allow motion of a mechanical oscillator to be squeezed below the zero-point motion. Of existing methods, mechanical parametric amplification is relatively accessible, but previously thought to be limited to 3dB of squeezing…
A beam of super-thermal, hot electrons was injected into maxwellian plasma with a density gradient along a magnetic field line. 1.5D particle-in-cell simulations were carried out which established that the EM emission is produced by the…
Absorption of surface acoustic waves by a two-dimensional electron gas in a perpendicular magnetic field is considered. The structure of such system at the filling factor $\nu$ close to 1/2 can be understood as a gas of {\em composite…
We present the numerical simulations for an electron-beam-driven and loss-cone-driven electron-cyclotron maser (ECM) with different plasma parameters and different magnetic field strengths for a relatively small region and short time-scale…
A new mechanisms for damping of slow magnetosonic waves (SMW) by pressure induced oscillations of the ionization degree is proposed. An explicit formula for the damping rate is quantitatively derived. Physical conditions where the new…
In this study, we experimentally investigate the application of a transient signal with complex frequencies to the absorption and transmission of sound waves. Indeed, the emission of a wave with an exponentially varying amplitude in time is…
An eikonal expansion is used to provide systematic corrections to the eikonal approximation through order $1/k^2$, where $k$ is the wave number. Electron wave functions are obtained for the Dirac equation with a Coulomb potential. They are…
We present an analysis of enhanced wave transmission through random media with mirror symmetry about a reflecting barrier. The mathematical model is the acoustic wave equation and we consider two setups, where the wave propagation is along…
Acoustic wave propagation in bulk GaN Semiconductor in the presence of a slowly changing a.c electric field and a constant electric field has been studied. Analytical expression for the attenuation (amplification) coefficient has been…
We report the development of the frequency-modulation (FM) method for measuring electron spin resonance (ESR) absorption in the 210-420 GHz frequency range. We demonstrate that using a high-frequency ESR spectrometer without resonating…
We propose a new approximation for the cyclo-synchrotron emissivity of a single electron. In the second part of this work, we discuss a simple application for our approximation, and investigate the heating of electrons through the…
Quantum parametric amplifiers typically generate by operating in proximity to a point of dynamical instability. We consider an alternate general strategy where quantum-limited, large-gain amplification is achieved without any proximity to a…
The statistical behavior of the eigenvalues of the sample covariance matrix (SCM) plays a key role in determining the performance of adaptive beamformers (ABF) in presence of noise. This paper presents a method to compute the approximate…
The electromagnetic (EM) radiation force-per-length exerted on a pair of electrically-conducting cylindrical particles of circular and non-circular cross-sections is examined using a formal semi-analytical method based on boundary matching…
Experiments provide a qualitative confirmation of significant absorption of a wide electromagnetic beam propagating along a thin conducting cylinder (the diameter of the cylinder can be orders of magnitude less than the beam waist width).…
Here we analyse ways to achieve deep subthreshold parametric squeezing of fluctuations beyond the $-6$~dB limit of single degree-of-freedom parametric resonators. One way of accomplishing this is via a lock-in amplifier feedback loop.…
This paper aims to mathematically advance the field of quantitative thermo-acoustic imaging. Given several electromagnetic data sets, we establish for the first time an analytical formula for reconstructing the absorption coefficient from…