Effect of an electric field on the energy spectrum and hydrodynamics of superfluid helium

1986 ◽  
Vol 34 (5) ◽  
pp. 1900-1905
Author(s):  
P. N. Brusov ◽  
E. D. Gutlyanskii ◽  
V. N. Popov
Keyword(s):  
Energy Spectrum ◽  
Electric Field ◽  
Superfluid Helium

Dirac particle in electric field with confining scalar potential on (anti)-de Sitter background

2018 ◽  
Vol 33 (34) ◽  
pp. 1850202 ◽  
Author(s):  
N. Messai ◽  
B. Hamil ◽  
A. Hafdallah
Keyword(s):  
Energy Spectrum ◽  
Dirac Equation ◽  
Electric Field ◽  
Scalar Potential ◽  
Dirac Particle ◽  
Wave Functions ◽  
De Sitter ◽  
Sitter Background ◽  
Position Representation

In this paper, we study the (1 + 1)-dimensional Dirac equation in the presence of electric field and scalar linear potentials on (anti)-de Sitter background. Using the position representation, the energy spectrum and the corresponding wave functions are exactly obtained.

ELECTROMAGNETIC CONTROL OF DYNAMICAL LOCALIZATION CONDITIONS IN 1D LATTICES WITH LONG-RANGE INTERSITE INTERACTIONS

2009 ◽  
Vol 07 (supp01) ◽  
pp. 149-154
Author(s):  
MARIA ANASTASIA JIVULESCU ◽  
ROSANNA MIGLIORE ◽  
ANTONINO MESSINA
Keyword(s):  
Charged Particle ◽  
Energy Spectrum ◽  
Electric Field ◽  
Long Range ◽  
Dynamical Localization ◽  
Bichromatic Field ◽  
Electromagnetic Control ◽  
Tunneling Dynamics ◽  
Localization Conditions

In this paper we investigate the possibility of controlling dynamical localization conditions for a charged particle confined in a 1D lattice biased with a dc-bichromatic field and long-range intersite interactions. We derive the quasi-energy spectrum of the system proving that the tunneling dynamics of the particle can be destroyed provided that the parameters of the external irradiating electric field are properly chosen.

Dirac oscillator in a uniform electric field: Path integral treatment

2019 ◽  
Vol 34 (30) ◽  
pp. 1950246
Author(s):  
Hassene Bada ◽  
Mekki Aouachria
Keyword(s):  
Energy Spectrum ◽  
Electric Field ◽  
Path Integral ◽  
Uniform Electric Field ◽  
Two Dimensional ◽  
Dirac Oscillator ◽  
Fermionic Model ◽  
Internal Motions ◽  
Integral Treatment ◽  
The One

In this paper, the propagator of a two-dimensional Dirac oscillator in the presence of a uniform electric field is derived by using the path integral technique. The fact that the globally named approach is used in this work redirects, beforehand, our search for the propagator of the Dirac equation to that of the propagator of its quadratic form. The internal motions relative to the spin are represented by two fermionic oscillators, which are described by Grassmannian variables, according to Schwinger’s fermionic model. Once the integration over the anticommuting variables (Grassmannian variables) is accomplished, the problem becomes the one of finding a non-relativistic propagator with only bosonic variables. The energy spectrum of the electron and the corresponding eigenspinors are also obtained in this work.

scholarly journals The Stark effect with minimum length

2017 ◽  
Vol 32 (02n03) ◽  
pp. 1750010 ◽  
Author(s):  
H. L. C. Louzada ◽  
H. Belich
Keyword(s):  
Perturbation Theory ◽  
Energy Spectrum ◽  
Hydrogen Atom ◽  
Electric Field ◽  
Stark Effect ◽  
Heisenberg Algebra ◽  
Uniform Electric Field ◽  
Minimum Length

We will study the splitting in the energy spectrum of the hydrogen atom subjected to an uniform electric field (Stark effect) with the Heisenberg algebra deformed leading to the minimum length. We will use the perturbation theory for cases not degenerate (n[Formula: see text]=[Formula: see text]1) and degenerate (n[Formula: see text]=[Formula: see text]2), along with known results of corrections in these levels caused by the minimum length applied purely to the hydrogen atom, so that we may find and estimate the corrections of minimum length applied to the Stark effect.

scholarly journals The Ultimate Ballistic Drift Velocity in Carbon Nanotubes

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammad Taghi Ahmadi ◽  
Razali Ismail ◽  
Michael L. P. Tan ◽  
Vijay K. Arora
Keyword(s):  
Energy Spectrum ◽  
Electric Field ◽  
Carrier Concentration ◽  
Drift Velocity ◽  
Mean Free Path ◽  
High Electric Field ◽  
Fermi Velocity ◽  
Zero Field ◽  
Saturation Velocity ◽  
The Mean

The carriers in a carbon nanotube (CNT), like in any quasi-1-dimensional (Q1D) nanostructure, have analog energy spectrum only in the quasifree direction; while the other two Cartesian directions are quantum-confined leading to a digital (quantized) energy spectrum. We report the salient features of the mobility and saturation velocity controlling the charge transport in a semiconducting single-walled CNT (SWCNT) channel. The ultimate drift velocity in SWCNT due to the high-electric-field streaming is based on the asymmetrical distribution function that converts randomness in zero-field to a stream-lined one in a very high electric field. Specifically, we show that a higher mobility in an SWCNT does not necessarily lead to a higher saturation velocity that is limited by the mean intrinsic velocity depending upon the band parameters. The intrinsic velocity is found to be appropriate thermal velocity in the nondegenerate regime, increasing with the temperature, but independent of carrier concentration. However, this intrinsic velocity is the Fermi velocity that is independent of temperature, but depends strongly on carrier concentration. The velocity that saturates in a high electric field can be lower than the intrinsic velocity due to onset of a quantum emission. In an SWCNT, the mobility may also become ballistic if the length of the channel is comparable or less than the mean free path.

scholarly journals Polar cap arcs from the magnetosphere to the ionosphere: kinetic modelling and observations by Cluster and TIMED

2012 ◽  
Vol 30 (2) ◽  
pp. 283-302 ◽  
Author(s):  
R. Maggiolo ◽  
M. Echim ◽  
C. Simon Wedlund ◽  
Y. Zhang ◽  
D. Fontaine ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Electric Field ◽  
Large Scale ◽  
Kinetic Modelling ◽  
Ion Beam ◽  
Potential Drop ◽  
Coupling Model ◽  
Optical Observations ◽  
Topside Ionosphere ◽  
Polar Cap

Abstract. On 1 April 2004 the GUVI imager onboard the TIMED spacecraft spots an isolated and elongated polar cap arc. About 20 min later, the Cluster satellites detect an isolated upflowing ion beam above the polar cap. Cluster observations show that the ions are accelerated upward by a quasi-stationary electric field. The field-aligned potential drop is estimated to about 700 V and the upflowing ions are accompanied by a tenuous population of isotropic protons with a temperature of about 500 eV. The magnetic footpoints of the ion outflows observed by Cluster are situated in the prolongation of the polar cap arc observed by TIMED GUVI. The upflowing ion beam and the polar cap arc may be different signatures of the same phenomenon, as suggested by a recent statistical study of polar cap ion beams using Cluster data. We use Cluster observations at high altitude as input to a quasi-stationary magnetosphere-ionosphere (MI) coupling model. Using a Knight-type current-voltage relationship and the current continuity at the topside ionosphere, the model computes the energy spectrum of precipitating electrons at the top of the ionosphere corresponding to the generator electric field observed by Cluster. The MI coupling model provides a field-aligned potential drop in agreement with Cluster observations of upflowing ions and a spatial scale of the polar cap arc consistent with the optical observations by TIMED. The computed energy spectrum of the precipitating electrons is used as input to the Trans4 ionospheric transport code. This 1-D model, based on Boltzmann's kinetic formalism, takes into account ionospheric processes such as photoionization and electron/proton precipitation, and computes the optical and UV emissions due to precipitating electrons. The emission rates provided by the Trans4 code are compared to the optical observations by TIMED. They are similar in size and intensity. Data and modelling results are consistent with the scenario of quasi-static acceleration of electrons that generate a polar cap arc as they precipitate in the ionosphere. The detailed observations of the acceleration region by Cluster and the large scale image of the polar cap arc provided by TIMED are two different features of the same phenomenon. Combined together, they bring new light on the configuration of the high-latitude magnetosphere during prolonged periods of Northward IMF. Possible implications of the modelling results for optical observations of polar cap arcs are also discussed.

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