Short-wave excitations in non-local Gross-Pitaevskii model

@article{Ivashin2011ShortwaveEI,
  title={Short-wave excitations in non-local Gross-Pitaevskii model},
  author={A. Ivashin and Y. Polu{\'e}ktov},
  journal={Central European Journal of Physics},
  year={2011},
  volume={9},
  pages={857-864}
}
We show that a non-local form of the Gross-Pitaevskii equation describes not only long-wave excitations, but also the short-wave ones in Bose-condensate systems. At certain parameter values, the excitation spectrum mimics the Landau spectrum of quasi-particle excitations in superfluid helium with roton minimum. The excitation wavelength, at which the roton minimum exists, is close to the inter-particle interaction range. We determine how the roton gap and the effective roton mass depend on the… Expand

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References

SHOWING 1-10 OF 62 REFERENCES
A quasi-local Gross-Pitaevskii equation for attractive Bose-Einstein condensates
TLDR
It is proved rigorously the absence of collapse in the model, and the phenomenology found in the nonlocal model is very similar to that present in the reduced one with the nonlinear dispersion. Expand
Dynamics of quasicollapse in nonlinear Schrodinger systems with nonlocal interactions
TLDR
Evidence is presented in support of the hypothesis that nonlocal attractively interacting condensates cannot collapse under very general forms of the interaction, and there appear oscillations of the wave packet with a localized component whose size is of the order of the range of interactions. Expand
Roton-maxon spectrum and stability of trapped dipolar Bose-Einstein condensates.
TLDR
Pancake dipolar condensates can exhibit a roton-maxon character of the excitation spectrum, so far observed only in superfluid helium, and the spectrum and the border of instability are tunable by varying the particle density and the confining potential. Expand
Manifestations of the roton mode in dipolar Bose-Einstein condensates.
TLDR
It is found that a small perturbation in the trapping potential can lead to dramatic changes in the condensate's density profile for sufficiently large dipolar interaction strengths and trap aspect ratios. Expand
Self-consistent field model for spatially inhomogeneous Bose systems
A self-consistent field (SCF) model is constructed for spatially inhomogeneous Bose systems with broken symmetry. A system of self-consistent equations is obtained for the wave functions of theExpand
The role of pair correlations in the formation of the ground state and the elementary excitation spectrum in a superfluid Bose liquid (A Review)
The paradoxes and disparities in the contemporary microscopic theory of superfluid helium (He–II) are discussed along with possible ways of resolving them by taking pair correlations of 4He atomsExpand
Solitons in quasi-one-dimensional Bose-Einstein condensates with competing dipolar and local interactions
We study families of one-dimensional matter-wave bright solitons supported by the competition of contact and dipole-dipole (DD) interactions of opposite signs. Soliton families are found, and theirExpand
Solutions of Gross-Pitaevskii equations beyond the hydrodynamic approximation: Application to the vortex problem
We develop a multiscale technique to describe excitations of a Bose-Einstein condensate, whose characteristic scales are comparable to the healing length, thus going beyond the conventionalExpand
Structure of a quantized vortex in boson systems
SummaryFor a system of weakly repelling bosons, a theory of the elementary line vortex excitations is developed. The vortex state is characterised by the presence of a finite fraction of theExpand
Ground-State Energy and Excitation Spectrum of a System of Interacting Bosons
Properties of a boson gas at zero temperature are investigated by means of field-theoretic methods. Difficulties arising from the depletion of the ground state are resolved in a simple way by theExpand
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