共查询到20条相似文献,搜索用时 15 毫秒
1.
R. Khomeriki L. Tkeshelashvili T. Buishvili Sh. Revishvili 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(3):421-424
The pseudo-spin model for a double layer quantum Hall system with
the total landau level filling factor ν=1 is discussed. In contrast to the
“traditional” model where the interlayer voltage enters as a static magnetic field
along pseudo-spin hard axis, taking into account the realistic experimental
situation, in our model we interpret the influence of applied voltage
as a source of additional relaxation process in the double layer system.
We show that the Landau-Lifshitz equation for the considered pseudo-magnetic
system well describes existing experimental data and reduces to the dc driven and damped
sine-Gordon equation. As a result, the
mentioned model predicts novel directed intra-layer transport phenomenon in
the system. In particular, unidirectional intra-layer
energy transport can be realized due to the motion of
topological kinks induced by applied voltage. Experimentally this should be manifested as
counter-propagating intra-layer inhomogeneous charge currents
proportional to the interlayer voltage and total topological charge of the
pseudo-spin system. 相似文献
2.
N.A. Kostov 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):255-259
We consider quasi-periodic and periodic (cnoidal) wave solutions of a set of n-component dynamical systems related to Korteweg-de Vries equation. Quasi-periodic wave solutions for these systems are expressed
in terms of Novikov polynomials. Periodic solutions in terms of Hermite polynomials and generalized Hermite polynomials for
dynamical systems related to Korteweg-de Vries equation are found.
Received 15 October 2001 / Received in final form 6 March 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: nakostov@ie.bas.bg 相似文献
3.
E. Arévalo Yu. Gaididei F.G. Mertens 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,27(1):63-74
We investigate the dynamics of a lattice soliton on a monatomic chain in the presence of damping and external forces. We consider
Stokes and hydrodynamical damping. In the quasi-continuum limit the discrete system leads to a damped and forced Boussinesq
equation. By using a multiple-scale perturbation expansion up to second order in the framework of the quasi-continuum approach
we derive a general expression for the first-order velocity correction which improves previous results. We compare the soliton
position and shape predicted by the theory with simulations carried out on the level of the monatomic chain system as well
as on the level of the quasi-continuum limit system. For this purpose we restrict ourselves to specific examples, namely potentials
with cubic and quartic anharmonicities as well as the truncated Morse potential, without taking into account external forces.
For both types of damping we find a good agreement with the numerical simulations both for the soliton position and for the
tail which appears at the rear of the soliton. Moreover we clarify why the quasi-continuum approximation is better in the
hydrodynamical damping case than in the Stokes damping case.
Received 22 August 2001 and Received in final form 7 December 2001 相似文献
4.
E. Nissimov S. Pacheva 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):197-201
The recently proposed supersymmetric extensions of reduced Kadomtsev-Petviashvili (KP) integrable hierarchies in N = 1, 2 superspace are shown to contain in the purely bosonic limit new types of ordinary non-supersymmetric integrable systems.
The latter are coupled systems of several multi-component non-linear Schr?dinger-like hierarchies whose basic nonlinear evolution
equations contain additional quintic and higher-derivative nonlinear terms. Also, we obtain the N = 2 supersymmetric extension of Toda chain model as Darboux-B?cklund orbit of the simplest reduced N = 2 super-KP hierarchy and find its explicit solution.
Received 13 September 2001 Published online 2 October 2002
RID="a"
ID="a"e-mail: nissimov@inrne.bas.bg
RID="b"
ID="b"e-mail: svetlana@inrne.bas.bg 相似文献
5.
S.B. Leble 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):189-192
Schlesinger transformations are considered as special cases of elementary Darboux transformations of an aaabstract Zakharov-Shabat
operator analog and its conjugate in differential rings and modules. The respective x- and t-chains of the transformations for potentials are constructed. Transformations that are combinations of the elementary ones
for the special choice of direct and conjugate problems (named as binary ones) are applied within some constraints setting
(reductions) for solutions. The geometric structures: Darboux surfaces, Bianchi-Lie formula for (nonabelian) rings are specified.
The applications in spectral operator and soliton theories are outlined.
Received 12 June 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: leble@mif.fg.gda.pl 相似文献
6.
P.L. Christiansen Y.B. Gaididei F.G. Mertens S.F. Mingaleev 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,19(4):545-553
We investigate the properties of nonlinear excitations in different types of soliton carrying systems with long-range dispersive interactions. We show that length-scale competition in such systems, universally results in a multi-component structure of nonlinear excitations
which may lead to a new type of multistability: coexistence of different nonlinear excitations at the same value of the spectral parameter (i.e., velocity in the case of anharmonic lattices or frequency in nonlinear Schr?dinger models).
Received 31 August 2000 and Received in final form 14 December 2000 相似文献
7.
We investigate stationary and travelling wave solutions of the classical one-dimensional transverse field Ising model. Results
are given on the existence, shape and stability of kink solutions and periodic solutions. We review recent analytical results
(e.g., the proof of existence of a one-parameter family of stationary kink solutions and the proof of existence of travelling wave
kink solutions with nonzero velocity c≠ 0) and extend them by the use of numerical methods. Small oscillations arising in the tails of travelling kink solutions
are investigated numerically. In the end, stability analysis puts some light on pinning effects.
Received 23 February 2001 and Received in final form 4 October 2001 相似文献
8.
In this work, we present a model and a method to study integer quantum Hall (IQH) systems. Making use of the Landau levels structure we divide these two-dimensional systems into a set of interacting one-dimensional gases, one for each guiding center. We show that the so-called strong field approximation, used by Kallin and Halperin and by MacDonald, is equivalent, in first order, to a forward scattering approximation and analyze the IQH systems within this approximation. Using an appropriate variation of the Landau level bosonization method we obtain the dispersion relations for the collective excitations and the single-particle spectral functions. For the bulk states, these results evidence a behavior typical of non-normal strongly correlated systems, including the spin-charge splitting of the single-particle spectral function. We discuss the origin of this behavior in the light of the Tomonaga-Luttinger model and the bosonization of two-dimensional electron gases. 相似文献
9.
By replacing quasiparticles by quasiskyrmions, we calculate the binding energy of the alpha-particle using the cluster expansion
method.
Received: 8 November 2001 / Accepted: 3 April 2002 相似文献
10.
V.S. Gerdjikov G.G. Grahovski N.A. Kostov 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):243-248
The class of nonlinear evolution equations (NLEE) - gauge equivalent to the N-wave equations related to the simple Lie algebra are derived and analyzed. They are written in terms of (x, t) ∈ satisfying r = rank nonlinear constraints. The corresponding Lax pairs and the time evolution of the scattering data are found. The Zakharov-Shabat
dressing method is appropriately modified to construct their soliton solutions.
Received 20 October 2001 / Received in final form 30 April 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: gerjikov@inrne.bas.bg 相似文献
11.
V. B. Shikin 《JETP Letters》2001,73(5):246-249
A generalization of the known theory describing the Hall channels with integer filling factors in inhomogeneous 2D electronic samples to the case of a stationary nonequilibrium state (with a nonzero Hall voltage V H across the 2D system) is proposed. For the central strip located near the extremum of the electron density, the theory predicts a change in its width and a shift of the whole strip from the equilibrium position as functions of V H . The theoretical results are used to interpret recent experiments on measuring the local electric fields along the Hall samples both in equilibrium conditions and in the presence of transport in the quantum Hall regime. 相似文献
12.
The plateau-insulator (PI) transition in the quantum Hall regime, in remarkable contrast to the plateau-plateau (PP) transition, exhibits very special features that enable one for the first time to disentwine the quantum critical aspects of the electron gas (scaling functions, critical indices) from the sample dependent effects of macroscopic inhomogeneities (contact misalignments, density gradients). In this communication we report new experimental data taken from the PI transition of a low-mobility InGaAs/InP heterostructure and propose universal scaling functions for the transport coefficients. Our new findings elucidate fundamental theoretical aspects of quantum criticality that have so far remained inaccessible. 相似文献
13.
Sen-yue Lou Ji Lin Xiao-yan Tang 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,22(4):473-478
The Painlevé integrability of the 2+1 dimensional AKNS system is proved. Using the standard truncated Painlevé expansion which
corresponds to a special B?cklund transformation, some special types of the localized excitations like the solitoff solutions,
multi-dromion solutions and multi-ring soliton solutions are obtained.
Received 31 January 2001 and Received in final form 15 May 2001 相似文献
14.
A.S. Kovalev F.G. Mertens H.J. Schnitzer 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,33(2):133-145
The dynamics of a non-planar vortex in a two-dimensional easy-plane ferromagnet of finite size is studied. Spin dynamics
simulations show small cycloidal oscillations of the vortex around its mean path. In contrast to an earlier phenomenological
theory we give a physical explanation: The oscillations occur due to the interaction of the vortex with coherent spin waves
which are excited by this vortex at the moment when it starts to move, in order to conserve the total energy and angular momentum.
The calculation of these quantities yields the frequencies and amplitudes of the cycloidal oscillations in good agreement
with the simulation data.
Received 9 December 2002 Published online 4 June 2003
RID="a"
ID="a"e-mail: franz.mertens@uni-bayreuth.de 相似文献
15.
P.G. Kevrekidis B.A. Malomed Z. Musslimani 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(3):421-436
A model including two nonlinear chains with linear and nonlinear couplings between them, and opposite signs of the discrete
diffraction inside the chains, is introduced. In the case of the cubic [ χ(3)] nonlinearity, the model finds two different interpretations in terms of optical waveguide arrays, based on the diffraction-management
concept. A continuum limit of the model is tantamount to a dual-core nonlinear optical fiber with opposite signs of dispersions
in the two cores. Simultaneously, the system is equivalent to a formal discretization of the standard model of nonlinear optical
fibers equipped with the Bragg grating. A straightforward discrete second-harmonic-generation [ χ(2)] model, with opposite signs of the diffraction at the fundamental and second harmonics, is introduced too. Starting from
the anti-continuum (AC) limit, soliton solutions in the χ(3) model are found, both above the phonon band and inside the gap. Solitons above the gap may be stable as long as they exist,
but in the transition to the continuum limit they inevitably disappear. On the contrary, solitons inside the gap persist all
the way up to the continuum limit. In the zero-mismatch case, they lose their stability long before reaching the continuum
limit, but finite mismatch can have a stabilizing effect on them. A special procedure is developed to find discrete counterparts
of the Bragg-grating gap solitons. It is concluded that they exist at all the values of the coupling constant, but are stable
only in the AC and continuum limits. Solitons are also found in the χ(2) model. They start as stable solutions, but then lose their stability. Direct numerical simulations in the cases of instability
reveal a variety of scenarios, including spontaneous transformation of the solitons into breather-like states, destruction
of one of the components (in favor of the other), and symmetry-breaking effects. Quasi-periodic, as well as more complex,
time dependences of the soliton amplitudes are also observed as a result of the instability development.
Received 14 September 2002 / Received in final form 4 February 2003 Published online 24 April 2003
RID="a"
ID="a"e-mail: malomed@eng.tau.ac.il 相似文献
16.
S. K. Adhikari 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(2):157-160
We use a time-dependent dynamical mean-field-hydrodynamic
model to predict and study bright solitons in a degenerate
fermion-fermion mixture in a quasi-one-dimensional cigar-shaped geometry
using variational and numerical methods.
Due to a strong Pauli-blocking repulsion among identical spin-polarized
fermions at short distances there cannot be bright solitons for
repulsive interspecies fermion-fermion interactions. However,
stable bright solitons can be formed for a sufficiently
attractive interspecies interaction. We perform a
numerical stability analysis of these solitons and also demonstrate the
formation of soliton trains. These fermionic solitons can be formed and
studied in laboratory with present technology. 相似文献
17.
H. Weigel 《The European Physical Journal A - Hadrons and Nuclei》1998,2(4):391-402
Abstact: Within an extended Skyrme soliton model for baryons the interplay between the collective radial motion and the SU(3)–flavor–rotations
is investigated. The coupling between these modes is mediated by flavor symmetry breaking. Collective coordinates which describe
the corresponding large amplitude fluctuations are introduced and treated canonically. When diagonalizing the resulting Hamiltonian
flavor symmetry breaking is fully taken into consideration. As eigenstates not only the low–lying (1/2)+ and (3/2)+ baryons but also their radial excitations are obtained and compared to the empirical data. In particular the relevance of
radial excitations for the penta–quark baryon Z
+ (Y=2, I=0, J
π=(1/2)+) is discussed. In this approach its mass is predicted to be 1.58 GeV. Furthermore the widths for various hadronic decays
are estimated which, for example, yields Γ(Z
+→NK) ∼ 100 MeV for the only permissible decay process of the Z
+.
Received: 20 April 1998 / Revised version: 29 May 1998 相似文献
18.
Analysis of edge-state energies in the integer quantum
Hall effect is carried out within the semiclassical approximation.
When the system is wide so that each edge can be considered
separately, this problem is equivalent to that of a one dimensional
harmonic oscillator centered at x = xc and an infinite wall at
x = 0, and appears in numerous physical contexts. The eigenvalues
En(xc) for a given quantum number n are solutions of the
equation S(E,xc)=π[n+ γ(E,xc)] where S is the WKB
action and 0 < γ < 1 encodes all the information on the
connection procedure at the turning points.
A careful implication of the WKB connection formulae results in an
excellent approximation to the exact energy eigenvalues. The
dependence of γ[En(xc),xc] ≡γn(xc)
on xc is analyzed between its two extreme values
as xc ↦-∞ far inside the sample
and as xc ↦∞ far outside the sample.
The edge-state energiesEn(xc) obey an almost exact scaling
law of the form
and the scaling function f(y) is explicitly elucidated. 相似文献
19.
S. Murugesh Radha Balakrishnan 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):193-196
We apply our recent formalism establishing new connections between the geometry of moving space curves and soliton equations,
to the nonlinear Schr?dinger equation (NLS). We show that any given solution of the NLS gets associated with three distinct
space curve evolutions. The tangent vector of the first of these curves, the binormal vector of the second and the normal
vector of the third, are shown to satisfy the integrable Landau-Lifshitz (LL) equation = ×, ( = 1). These connections enable us to find the three surfaces swept out by the moving curves associated with the NLS. As an
example, surfaces corresponding to a stationary envelope soliton solution of the NLS are obtained.
Received 5 December 2001 Published online 2 October 2002
RID="a"
ID="a"e-mail: radha@imsc.ernet.in 相似文献
20.
S. Villain-Guillot C. Josserand 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):305-309
We develop a new technique describing the non linear growth of interfaces. We apply this analytical approach to the one dimensional
Cahn-Hilliard equation. The dynamics is captured through a solvability condition performed over a particular family of quasi-static
solutions. The main result is that the dynamics along this particular class of solutions can be expressed in terms of a simple
ordinary differential equation. The density profile of the stationary regime found at the end of the non-linear growth is
also well characterized. Numerical simulations are compared in a satisfactory way with the analytical results through three
different fitting methods and asymptotic dynamics are well recovered, even far from the region where the approximations hold.
Received 16 October 2001 / Received in final form 15 March 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: josseran@lmm.jussieu.fr
RID="b"
ID="b"UMR CNRS 7607 相似文献