ar X iv : c on d - m at / 0 30 41 48 v 1 7 A pr 2 00 3 Deformation of dark solitons in inhomogeneous
نویسندگان
چکیده
A dark soliton becomes unstable when it is incident on a background density gradient, and the induced instability results in the emission of sound. Detailed quantitative studies of sound emission are performed for various potentials, such as steps, linear ramps and gaussian traps. Continuous emission of sound is found to lead to an apparent deformation of the soliton profile. The power emitted by the soliton is shown to be parametrised by the square of the displacement of the centre of mass of the soliton from its density minimum, thus highlighting the significance of the inhomogeneity-induced soliton deformation.
منابع مشابه
ar X iv : c on d - m at / 0 30 41 48 v 2 3 J un 2 00 3 Deformation of dark solitons in inhomogeneous
A dark soliton becomes unstable when it is incident on a background density gradient, and the induced instability results in the emission of sound. Detailed quantitative studies of sound emission are performed for various potentials, such as steps, linear ramps and gaussian traps. The amount of sound emission is found to be a significant fraction of the soliton energy for typical potentials. Co...
متن کاملar X iv : c on d - m at / 0 10 30 52 v 1 2 M ar 2 00 1 NMR Frequencies of a Splay Soliton in 3 He - A
Superfluid 3 He-A has domain-wall like structures, which are called solitons. We calculate numerically the structure of a splay soliton and study its effect on the NMR spectrum by calculating the frequency and the amplitude of the soliton peaks. We compare the results with experiments and discuss their implications on the basic parameters of 3 He.
متن کاملar X iv : c on d - m at / 0 31 10 59 v 1 4 N ov 2 00 3 Dark Matter - Wave Solitons in Optical Lattices
We analyze the Floquet-Bloch matter-wave spectrum of Bose-Einstein condensates loaded into single-periodic optical lattices and double-periodic superlattices. In the framework of the Gross-Pitaevskii equation, we describe the structure and analyze the mobility properties of dark matter-wave solitons residing on the background of extended nonlinear Bloch-type states. We demonstrate that interact...
متن کاملar X iv : c on d - m at / 0 30 41 81 v 2 1 3 M ay 2 00 3 DCPT - 03 / 17 Hexagonal lattices and nanotubes
We consider a Fröhlich-type Hamiltonian on a hexagonal lattice. Aiming to describe nanotubes, we choose this 2-dimensional lattice to be periodic and to have a large extension in one (x) direction and a small extension in the other (y) direction. We study the existence of solitons in this model using both analytical and numerical methods. We find exact solutions of our equations and discuss som...
متن کاملar X iv : h ep - t h / 03 02 00 7 v 3 2 8 A pr 2 00 3 April 2003 Stability Issues for w < − 1 Dark Energy
Precision cosmological data hint that a dark energy with equation of state w = P/ρ < −1 and hence dubious stability is viable. Here we discuss for any w nucleation from Λ > 0 to Λ = 0 in a first-order phase transition. The critical radius is argued to be at least of galactic size and the corresponding nucleation rate glacial, thus underwriting the dark energy’s stability and rendering remote an...
متن کامل