A mechanism for spin electron acoustic soliton observed in a spin polarized nanosized electron-hole plasma

The formation and the characteristics of spin electron acoustic (SEA) soliton in a beam interacting spin polarized electron-hole plasma are investigated. These wavepackets are supposed to be the source of heating during the excitation process. We have used the separate spin evolution-quantum hydrodynamic (SSE-QHD) model along with Maxwell equations and derived the Korteweg-de Vries (KdV) equation by using the reductive perturbation method (RPM). We note that the larger values of beam density and spin polarization can change the soliton nature from rarefactive to compressive. Our findings may be important to understand the characteristics of localized spin dependent nonlinear waves in nanosized semiconductor devices.

Quantum Energy-Transport and Drift-Diffusion Models for Electron Transport in Graphene An Approach by The Wigner Function

The present work aims at formulating quantum energy-transport and drift- diffusion equations for charge transport in graphene from a quantum hydrodynamic model proposed in [1], obtained from the Wigner-Boltzmann equation via the mo- ment method. In analogy with the semiclassical case, we are confident that the energy- transport and drift-diffusion models have mathematical properties which allow an easier numerical treatment.

Stopping Power Modulation by Pump Waves of Charged Particles Moving above Two-Dimensional Electron Gases

The perturbation electron density and stopping power caused by the movement of charged particles above two-dimensional quantum electron gases (2DQEG) have been studied in numerous works using the quantum hydrodynamic (QHD) theory. In this paper, the QHD is modified by introducing the two-dimensional electron exchange-correlation potential at high density V x c 2 DH and the pump wave modulations. Based on the modified QHD, the perturbation electron density and stopping power are calculated for pump waves with various parameters. The results show that the stopping power values are more accurate after considering V x c 2 DH . Under the modulation of pump waves with the wavelength from 0.1 nm to 0.1 cm , the perturbation electron density of 2DQEG and the stopping power of charged particles show periodic changes. Under the modulation of pump waves with λ = 1.76 × 10 − 4 cm and Φ 0 = 2 × 10 10 e / λ f , the average stopping power with respect to the time phase θ becomes negative, which means that the charged particles will gain energy and can be accelerated. This is a new phenomenon in the fields of 2DQEG and of great significance in surface physics and surface modification in nanoelectronic devices with beam matter interactions.

Nonlocal Hydrodynamic Models for the Optical Response of Plasmonic Nanostructures

In order to model the interaction between light and plasmonic structures at deep-nanometer scale, which is governed by non-classical effects, a nonlocal hydrodynamic approach has been extensively studied. Several hydrodynamic models have been proposed, solving the coupled equations: the linearized hydrodynamic equation of motion and the electrodynamic Maxwell’s equations, by employing additional boundary conditions. This work compares four hydrodynamic models: the hard wall hydrodynamic model (HW-HDM), the curl-free hydrodynamic model (CF-HDM), the shear forces hydrodynamic model (SF-HDM), and the quantum hydrodynamic model (Q-HDM). The analysis is conducted for a metallic spherical nanoparticle, as an example. The above hydrodynamic models are also compared with experiments available in literature. It is demonstrated that HW-HDM and QHDM outperform the other two hydrodynamic models.