waves in a magnetic field

... hypothetical QWW with parabolic bands, but with the same parameters as in InSb/GaAs For a fixed value of d the binding energy in both cases increases as a function of the magnetic field due to the increasing ... 1,2—for the InSb/GaAs quantum wire; 10 ,20 —for semiconductor wire with standard dispersion law GaAs/AlAs nonparabolic dispersion law in comparison with a parabolic case As in [18] the binding energy ... difference in binding energies for InSb/GaAs and GaAs/AlAs are more ˚ ˚ essential for a 100 A wire than for 200 A wire for the same ˚ value of B = 10 T In the range B < 10 T (R = 200 A) , when the nonparabolicity...

Ngày tải lên: 22/06/2014, 18:20

... series in J The problem can be evaded within a mean field like treatment of the constraint, where the local constraint is replace by the thermal average: ∑⟨ ⟩ a+ (9) iα aiα = α The quation (7) is introduced ... unphysical contributions from all sites cancel and only the physical states survive in Z We apply the standard integrant formulation for the Hamiltonian (8) of the spin system in the Neel state in a ... global coordinate system to decribe the magnetic order Supposing that in the classical ground states a spin at site i is directed along some unit vector, we choose this classical spin orientation...

Ngày tải lên: 30/10/2015, 20:47

... perpendicular external magnetic field, both for the case of a single potential kink, as well as for a kink-antikink pair One advantage of such a setup is the fact that in an experimental realization of ... states that are indicated by arrows in panel (a) (a) (b) Figure Energy levels of a single kink profile in bilayer graphene as function of external magnetic field B0 with the same parameters as Fig ... curves in panels (a, b)) The inset of panel (a) indicates that the wavespinors satisfy the a1 = ϕb3 and ϕb1 = − a3 relations at ky = and B0 = which leads to a zero oscillator strength for the ® transition...

Ngày tải lên: 21/06/2014, 02:20

... of arbitrary transitions between the Landau levels The analytical result is numerically evaluated and graphed for a specific quantum well, GaAs/AlGaAs, to show clearly the dependence of the Hall ... Numerical results and discussion are given in Sec III Finally, remarks and conclusions are shown briefly in Sec IV II HALL EFFECT IN PARABOLIC QUANTUM WELLS IN THE PRESENCE OF A LASER RADIATION ... factor of electron By using Hamiltonian (4) and the procedures as in the works [9-14], we obtain the quantum kinetic equation for electrons in the single (constant) scattering time approximation...

Ngày tải lên: 31/10/2015, 10:41

... gauge transformations Problem 14 Lagrangian of Charged Particle in Electromagnetic Field Show that the Lagrangian of a particle with the charge q moving with the velocity v in an electromagnetic ... eigenfrequencies for an isotropic three-dimensional harmonic oscillator realized as a particle of charge q placed in a uniform magnetic, B, and electric, E, fields which are mutually perpendicular and take their ... don’t change when the potentials are transformed according to: ϕ =ϕ− ∂ψ , ∂t A =A+ ψ, (13) where ψ is an arbitrary function of the coordinates and time These transformations are known as the gauge...

Ngày tải lên: 24/05/2014, 19:10

... to gauge invariant quantity, magnetic flux through solenoid AB effect measured many times, starting with Chambers5 and Furry and Ramsey6 The latter authors used a long magnetic whisker in place ... QM gauge transformations (11) Require that a QM gauge tranformation should take wave fctn ψ and potentials A, φ to physically equivalent set ψ , A , φ Can accomplish this by taking transformation ... solenoidal vector potential can be written (cylindrical coordinates ρ, z, θ) A= Az = A = 0, A = B0 ρ/2 ρ a (20) electrostatic potential case, i.e that ψ =...

Ngày tải lên: 24/05/2014, 19:10

... “diffusion part” and a nonlinear “reaction part.” However, Advances in Difference Equations the reaction part consists of a quadratic polynomial so that the investigation is reduced to a linear and homogeneous ... called a traveling wave with velocity −δ/τ if vi t τ t vi δ , t ∈ N, i ∈ Z 2.9 In case δ and τ 1, our traveling wave is also called a standing wave Next, recall that a positive integer ω is called ... of traveling waves with arbitrarily given least spatial periods and least temporal periods and traveling speeds Therefore, we may now answer our original question as follows Suppose that we are...

Ngày tải lên: 21/06/2014, 20:20

... of an insulating ground state of neutral graphene was considered in [26] by means of tight-binding Hartree-Fock approximation It was shown that Landau level mixing favors formation of insulating ... of magnetoplasmons in graphene calculated numerically are shown Results obtained without taking into account Landau level mixing, with taking into account a mixing of two or three lowest Landau ... increasing a number of Landau levels taken into account Several lowest Landau levels are sufficient to obtain rather accurate results On the other hand, calculations in the lowest Landau level approximation,...

Ngày tải lên: 22/06/2014, 00:20

... Moreover at certain times, an observation arrives that constrains the state of the variable of interest at that time Multiple copies (particles) of the variable of interest are used, each one associated ... commands which are sent to the servos A forward kinematic model is then used to calculate the hip and ankle position in the Cartesian space Based on the kinematics analysis included in Appendix A, ... important because it can relate the image data with the real, three-dimensional world data Hence, the mapping 25 between the coordinates in the image plane and the coordinates in the physical 3D...

Ngày tải lên: 16/10/2015, 11:57

... maser features and the simultaneous dimming of nearby features can be interpreted as originating from the passage of a magnetohydrodynamic (MHD) shock (Alakoz et al 2005) The shock was probably ... VLA2, at a distance of 55 mas (±40 mas), or at the projected distance of 110 AU (±80 AU) Therefore, the OH masers may well be located in the same shell as the water masers The magnetic field in ... generated by the exciting star of VLA2 and propagated in the gas of the stellar wind Conclusions A very strong magnetic field of 40 mG has been detected in several OH masers spots which have appeared...

Ngày tải lên: 28/04/2014, 13:15

... direction maintained continuity and shape of the remaining cortical levels Trabecular proliferation was also apparent in a centripetal direction relative to the surgical cavity Medullary spaces showed ... Janeiro: Guanabara Koogan; 1994 Feinberg SE, Steinberg B, Helman JI: Healing of Traumatic Injuries In Oral and Maxillofacial Trauma Volume Edited by: Fonseca RJ, Walker RV Philadelphia: Saunders; ... Electrical Bone Graft Stimulation for Spinal Fusion: A Review Neurosurgery 2000, 47:1041-1056 Ishisaka R, Kanno T, Inai Y, Nakahara H, Akiyama J, Yoshioka T, Utsumi K: Effects of a magnetic field...

Ngày tải lên: 11/08/2014, 23:22

... the classical magnetic field, the effect also exists in the case of a quantized magnetic field, and the quantum acoustomagnetoelectric effects due to Rayleigh sound waves have investigated [14] ... the AME current I on acoustic wave numbers qz and on the parameters of the RQW with an infinite potential has been shown Numerical calculations are carried out with a specific GaAs rectangular ... considered classically, and weak thus limiting ourselves to the linear approximation of magnetic field H We shall consider a situation whereby the sound is propagating along the quantum wire axis (Oz),...

Ngày tải lên: 30/10/2015, 20:58

... magnetic field has one main maximum and several neighboring secondary maxima The further away from the main maximum, the secondary one is the smaller But in the case of absence of an external magnetic ... the GaAs − Al0.3 Ga0.7 As compositional superlattices II CALCULATIONS OF THE NONLINEAR ABSORPTION COEFFICIENT OF A STRONG ELECTROMAGNETIC WAVE BY CONFINED ELECTRONS IN A COMPOSITIONAL SUPERLATTICE ... low-dimensional systems are obtained The analytical expressions are numerically calculated and discussed to show the differences in comparison with the case of absence of an external magnetic with a specific...

Ngày tải lên: 31/10/2015, 10:40

... is due to spin-splitting in the parallel magnetic field leading to reduced screening in a spin-polarized electron gas We have also obtained similar results for RIS with zi = 490˚ A and Nid = 3.2 ... the finite temperature case and the results are displayed in Fig It is seen that the temperature dependence of the mobility is similar to that shown in Fig III.3 The magnetic field effects ˚ and ... mobility increases remarkably for high-density regions Gold has shown [1] that the low temperature experimental data given in [6] can also be interpreted using RIS and IRS We have generalized the Gold’s...

Ngày tải lên: 31/10/2015, 10:44

... specialization may be formulated as a spliting of states by means of additional features which in our case are POS tags In our HMM-based system the specialization strategy using POS information ... Molina and F Pla Shallow parsing using specialized hmms JMLR Special Issue on Machine Learning approaches to Shallow Pasing, 2002 [6] L R Rabiner A tutorial on hidden markov models and selected applications ... any word feature, which is incorporated into the model Moreover, transition feature functions may also take into account both a word and its features as, for instance, a word context A training...

Ngày tải lên: 24/04/2014, 13:21

... equal to the spiral arm separation, in a way quite similar to that observed in the Milky Way Intergalactic magnetic xelds The radio emission of distant quasars is also used to constrain the intensity ... [58] Alfven waves may also leave a signature on the CMBR anisotropies There are at least three main & reasons which make this kind of wave considerably interesting The "rst is that Alfven waves ... in some MHD dynamo mechanisms driving an instability of small-scale magnetic "elds into large-scale "elds A similar e!ect may take place at a cosmological level leading to signi"cative corrections...

Ngày tải lên: 24/04/2014, 17:19

Ngày tải lên: 13/05/2014, 09:18

... Bolognini N, Pascual-Leone A, Fregni F: Using non-invasive brain stimulation to augment motor training-induced plasticity J Neuroeng Rehabil 2009, 6:8 Kobayashi M, Pascual-Leone A: Transcranial magnetic ... Toronto, Ontario, M5S 1A1 , Canada Authors’ contributions HY was involved with model equation derivation, data analysis, and drafting of the manuscript MC was involved in generating figures MGF and PLC ... Mathematica 6.0 (Wolfram Research, Inc Champaign, IL) Numerical simulations were done with Matlab 7.4.0 (The MathWorks, Inc Natick, MA) Results Transmembrane potentials induced by a time-varying...

Ngày tải lên: 19/06/2014, 08:20

... is taken to minimize delays between head tracking devices and image updates, VR-induced retinal slip can be delivered in a controlled manner in order to cause adaptation A randomized trial has ... was based on average measurements of luminance obtained from products sampled at a local grocery store, using a luminance meter (LS-100 Luminance Light Meter, Minolta Corp Ramsey, NJ) The spatial ... rotating their head Nausea was significantly greater when subjects navigated using their head The lag between head movement and scene movement, and the variability in frame update rate has also been...

Ngày tải lên: 19/06/2014, 10:20

... surfaces Uniform distribution was obtained and adsorption was irreversible The density of a gold nanoparticle assembly was investigated and analyzed in relation to several parameters such as voltage, ... As the differences in particle concentration in the liquid have already been taken into account in the percentage values, the variations in deposited nanoparticle density are not solely explained ... ImageJ software on contrastenhanced images For one sample, the silicon substrate was replaced by a platinum-coated silicon substrate The platinum material was deposited by sputtering (under a...

Ngày tải lên: 20/06/2014, 22:20