Electric and magnetic field induced dimensionality reduction in InGaAs-GaAs superlattices

1992 ◽  
Vol 70 (10-11) ◽  
pp. 819-823 ◽  
Author(s):  
Alain Roth ◽  
Emmanuel Lugagne-Delpon ◽  
Paul Voisin
Keyword(s):  
Magnetic Field ◽  
Binding Energy ◽  
Magnetic Fields ◽  
Dimensionality Reduction ◽  
Oscillator Strength ◽  
Electric And Magnetic Fields ◽  
Electric And Magnetic Field ◽  
Exciton Interactions

We have measured photoconductivity spectra in a InGaAs/GaAs superlattice subjected to longitudinal electric and magnetic fields. We have observed a clear sharpening of the excitonic features in the spectra as the fields increases. Furthermore, the intensity of excitons involving spatially separated electrons and holes increases with increasing magnetic field relative to that of vertical excitons. These observations can be interpreted with a model that lakes into account exciton wavefunction shrinkage induced by magnetic field. Oblique excitons have a smaller binding energy than vertical excitons and are therefore more sensitive to magnetic localization, which enhances their oscillator strength relative to that of vertical excitons. Strong exciton interactions are also observed, giving rise to level anticrossings.

scholarly journals Charged Particle Trajectories in Static Electric and Magnetic Fields

1961 ◽  
Vol 14 (2) ◽  
pp. 310
Author(s):  
KJ Ausburn
Keyword(s):  
Magnetic Field ◽  
Charged Particle ◽  
Magnetic Fields ◽  
Analytical Solution ◽  
Arc Length ◽  
Intrinsic Interest ◽  
Field Distributions ◽  
Electric And Magnetic Fields ◽  
Electric And Magnetic Field ◽  
Curvature And Torsion

A trajectory passing through a given point in a given direction is completely determined if its curvature and torsion are known functions of its arc length. Relativistic expressions for the curvature and torsion in terms of the electric and magnetic field distributions are derived below. Besides their intrinsic interest these expressions may be useful in the analytical solution of some simple trajectory problems.

scholarly journals <i>Brief communication</i> "Modeling tornado dynamics and the generation of infrasound, electric and magnetic fields"

2010 ◽  
Vol 10 (2) ◽  
pp. 295-298 ◽  
Author(s):  
E. D. Schmitter
Keyword(s):  
Magnetic Field ◽  
Velocity Field ◽  
Magnetic Fields ◽  
Early Warning ◽  
Time Varying ◽  
Dust Devils ◽  
Model Calculations ◽  
Electric And Magnetic Fields ◽  
Electric And Magnetic Field ◽  
Insight Into

Abstract. Recent observations endorse earlier measurements of time varying electric and magnetic fields generated by tornadoes and dust devils. These signals may provide a means for early warning but together with a proper modeling approach can also provide insight into geometry and dynamics of the vortices. Our model calculations show the existence of pressure resonances characterized as acoustic duct modes with well defined frequencies. These resonances not only generate infrasound but also modulate the charge density and the velocity field and in this way lead to electric and magnetic field oscillations in the 0.5–20-Hz range that can be monitored from a distance of several kilometers.

scholarly journals Electric and Magnetic Field Effects in p-Methoxy Benzylidene p′-n-Butylaniline

1976 ◽  
Vol 31 (3-4) ◽  
pp. 283-287 ◽  
Author(s):  
N. V. S. Rao ◽  
P. R. Kishore ◽  
T. F. S. Raj ◽  
M. N. Avadhanlu ◽  
C. R. K. Murty
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Liquid Crystal ◽  
Magnetic Fields ◽  
Nematic Liquid Crystal ◽  
Nematic Phase ◽  
Relative Effectiveness ◽  
Magnetic Field Effects ◽  
Electric And Magnetic Fields ◽  
Electric And Magnetic Field

Molecular alignment in the nematic phase of p-methoxy benzylidene p′-n-butylaniline (MBBA) in the presence of electric and magnetic fields is investigated. The relative effectiveness of electric and magentic fields on the nematic liquid crystal MBBA is discussed. In the dielectric regime it is found that the threshold fields for chevron formation are considerably different from the threshold fields for inducing changes in the dielectric constant.

Schwinger effect in an instanton background with electric and magnetic fields via holography

2018 ◽  
Vol 33 (25) ◽  
pp. 1850144
Author(s):  
Maryam Gholizadeh Arashti ◽  
Majid Dehghani
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Production Rate ◽  
Pair Creation ◽  
Zero Temperature ◽  
Expectation Value ◽  
Background Magnetic Field ◽  
Electric And Magnetic Fields ◽  
Schwinger Effect ◽  
Horizon Limit

The Schwinger effect in the presence of instantons and background magnetic field was considered to study the dependence of critical electric field on instanton density and magnetic field using AdS/CFT conjecture. The gravity side is the near horizon limit of D3[Formula: see text]D(−[Formula: see text]1) background with electric and magnetic fields on the brane. Our approach is based on the potential analysis for particle–antiparticle pair at zero and finite temperatures, where the zero temperature case is a semi-confining theory. We find that presence of instantons suppresses the pair creation effect, similar to a background magnetic field. Then, the production rate will be obtained numerically using the expectation value of circular Wilson loop. The obtained production rate in a magnetic field is in agreement with previous results.

Modified Morris-Lecar neuron model: Effects of very low frequency electric fields and of magnetic fields on the local and network dynamics of an excitable media

2021 ◽  
Author(s):  
Karthikeyan Rajagopal ◽  
Irene Moroz ◽  
Balamurali Ramakrishnan ◽  
Anitha Karthikeyan ◽  
Prakash Duraisamy
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Field ◽  
Neuron Model ◽  
Low Noise ◽  
Spiral Waves ◽  
Excitable Media ◽  
Field Frequency ◽  
Electric And Magnetic Fields ◽  
Electric Field Frequency

Abstract A Morris-Lecar neuron model is considered with Electric and Magnetic field effects where the electric field is a time varying sinusoid and magnetic field is simulated using an exponential flux memristor. We have shown that the exposure to electric and magnetic fields have significant effects on the neurons and have exhibited complex oscillations. The neurons exhibit a frequency-locked state for the periodic electric field and different ratios of frequency locked states with respect to the electric field frequency is also presented. To show the impact of the electric and magnetic fields on network of neurons, we have constructed different types of network and have shown the network wave propagation phenomenon. Interestingly the nodes exposed to both electric and magnetic fields exhibit more stable spiral waves compared to the nodes exhibited only to the magnetic fields. Also, when the number of layers are increased the range of electric field frequency for which the layers exhibit spiral waves also increase. Finally the noise effects on the field affected neuron network are discussed and multilayer networks supress spiral waves for a very low noise variance compared against the single layer network.

scholarly journals Dynamics of an orbital polarization of twisted electron beams in electric and magnetic fields

2019 ◽  
Vol 204 ◽  
pp. 10008
Author(s):  
Alexander J. Silenko ◽  
Pengming Zhang ◽  
Liping Zou
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Magnetic Fields ◽  
Quantum Dynamics ◽  
Electron Beams ◽  
Equations Of Motion ◽  
Vortex Beam ◽  
Dirac Particles ◽  
Electric And Magnetic Fields ◽  
Average Projection

Relativistic classical and quantum dynamics of twisted (vortex) Dirac particles in arbitrary electric and magnetic fields is constructed. The relativistic Hamiltonian and equations of motion in the Foldy-Wouthuysen representation are derived. Methods for the extraction of an electron vortex beam with a given orbital polarization and for the manipulation of such a beam are developed. The new effect of a radiative orbital polarization of a twisted electron beam in a magnetic field resulting in a nonzero average projection of the intrinsic orbital angular momentum on the field direction is predicted.

PHONON CONFINEMENT EFFECT ON THE BINDING ENERGY OF A HYDROGENIC IMPURITY IN QUANTUM WIRES IN THE ELECTRIC AND MAGNETIC FIELDS

2012 ◽  
Vol 15 ◽  
pp. 184-190
Author(s):  
ABBAS SHAHBANDARI
Keyword(s):  
Binding Energy ◽  
Magnetic Fields ◽  
Quantum Wires ◽  
Polar Optical Phonon ◽  
Phonon Confinement ◽  
Hydrogenic Impurity ◽  
Bound Polaron ◽  
Electric And Magnetic Fields ◽  
Applied Fields ◽  
Variation Technique

The effect of phonon confinement on ground state binding energy of bound polaron in polar quantum wires with a finite confining potential investigated by Landau-Pekar variation technique. The effect of external electric and magnetic fields is taken into account as well. The obtained results show that the polar optical phonon confinement leads to a considerable enhancement of the polaron effect and these corrections increase with increasing of applied fields.

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