117 citations · 834 across the 23 of their papers we have counts for
23 papers
Perturbative nonlinear J-matrix method of scattering in two dimensions
T. J. Taiwo, A. D. Alhaidari, U. Al Khawaja
We introduce a perturbative formulation for a nonlinear extension of the J-matrix method of scattering in two dimensions. That is, we obtain the scattering matrix for the time-inde…
Unidirectional flow of flat-top solitons
M. O. D. Alotaibi, L. Al Sakkaf, U. Al Khawaja
We numerically demonstrate the unidirectional flow of flat-top solitons when interacting with two reflectionless potential wells with slightly different depths. The system is descr…
Reflectionless potentials and resonant scattering of flat-top and thin-top solitons
L. Al Sakkaf, U. Al Khawaja
We identify a class of potentials for which the scattering of flat-top solitons and thin-top solitons of the nonlinear Schrödinger equation with dual nonlinearity can be reflection…
New classes of solutions in the Coupled PT Symmetric Nonlocal Nonlinear Schrodinger Equations with Four Wave Mixing
P. S. Vinayagam, R. Radha, U. Al Khawaja +1
We investigate generalized nonlocal coupled nonlinear Schroedinger equation containing Self-Phase Modulation, Cross-Phase Modulation and Four-Wave Mixing involving nonlocal interac…
Expansion of fractional derivatives in terms of an integer derivative series: physical and numerical applications
Anastasia Gladkina, Gavriil Shchedrin, U. Al Khawaja +1
We use the displacement operator to derive an infinite series of integer order derivatives for the Grünwald-Letnikov fractional derivative and show its correspondence to the Rieman…
Collisional Dynamics of Solitons in the Coupled PT symmetric Nonlocal nonlinear Schrodinger equations
P. S. Vinayagam, R. Radha, U. Al Khawaja +1
We investigate the focusing coupled PT-symmetric nonlocal nonlinear Schrodinger equation employing Darboux transformation approach. We find a family of exact solutions including pa…
High-accuracy power series solutions with arbitrarily large radius of convergence for fractional nonlinear differential equations
U. Al Khawaja, M. Al-Refai, Lincoln D. Carr
Fractional nonlinear differential equations present an interplay between two common and important effective descriptions used to simplify high dimensional or more complicated theor…
Averaged dynamics of soliton molecules in dispersion-managed optical fibers
S. M. Alamoudi, U. Al Khawaja, B. B. Baizakov
The existence regimes and dynamics of soliton molecules in dispersion-managed (DM) optical fibers have been studied. Initially we develop a variational approximation (VA) for descr…
Stability of -soliton molecules in dispersion-managed optical fibers
Abdelâali Boudjemâa, U. Al Khawaja
We investigate the stability of -soliton molecules in dispersion-managed optical fibers with focus on the recently realized 2- and 3-soliton molecules. We calculate their bindin…
Directional flow of solitons with asymmetric potential wells: Soliton diode
M. Asad-uz-zaman, U. Al Khawaja
We study the flow of bright solitons through two asymmetric potential wells. The scattering of a soliton by certain type of single potential wells, e.g., Gaussian or Rosen-Morse, i…
Formation of matter-wave soliton molecules
U. Al Khawaja, H. T. C. Stoof
We propose a method of forming matter-wave soliton molecules that is inspired by the recent experiment of Dris {\it et al.}. In the proposed set-up we show that if two solitons are…
A comparative analysis of Painlevé, Lax Pair, and Similarity Transformation methods in obtaining the integrability conditions of nonlinear Schrödinger equations
U. Al Khawaja
We derive the integrability conditions of nonautonomous nonlinear Schrdinger equations using the Lax Pair and Similarity Transformation methods. We present a comparativ…
Stability and dynamics of two-soliton molecules
U. Al Khawaja
The problem of soliton-soliton force is revisited. From the exact two solitons solution of a nonautonomous Gross-Pitaevskii equation, we derive a generalized formula for the mutual…
Soliton localization in Bose-Einstein condensates with time-dependent harmonic potential and scattering length
U. Al Khawaja
We derive exact solitonic solutions of a class of Gross-Pitaevskii equations with time-dependent harmonic trapping potential and interatomic interaction. We find families of exact…
Feshbach resonances in an optical lattice
D. B. M. Dickerscheid, U. Al Khawaja, D. van Oosten +1
We present the theory for ultracold atomic gases in an optical lattice near a Feshbach resonance. In the single-band approximation the theory describes atoms and molecules which ca…
Dimensional and Temperature Crossover in Trapped Bose Gases
U. Al Khawaja, N. P. Proukakis, J. O. Andersen +2
We investigate the long-range phase coherence of homogeneous and trapped Bose gases as a function of the geometry of the trap, the temperature, and the mean-field interactions in t…
Low-dimensional Bose gases
U. Al Khawaja, J. O. Andersen, N. P. Proukakis +1
We present an improved many-body T-matrix theory for partially Bose-Einstein condensed atomic gases by treating the phase fluctuations exactly. The resulting mean-field theory is v…
Phase fluctuations in atomic Bose gases
J. O. Andersen, U. Al Khawaja, H. T. C Stoof
We improve on the Popov theory for partially Bose-Einstein condensed atomic gases by treating the phase fluctuations exactly. As a result, the theory becomes valid in arbitrary dim…
Nonlinear coupling between scissors modes of a Bose-Einstein condensate
U. Al Khawaja, H. T. C. Stoof
We explore the nonlinear coupling of the three scissors modes of an anisotropic Bose-Einstein condensate. We show that only when the frequency of one of the scissors modes is twice…
Skyrmion Physics in Bose-Einstein Ferromagnets
U. Al Khawaja, H. T. C. Stoof
We show that a ferromagnetic Bose-Einstein condensate has not only line-like vortex excitations, but in general also allows for point-like topological excitations, i.e., skyrmions.…
't Hooft-Polyakov Monopoles in an Antiferromagnetic Bose-Einstein Condensate
H. T. C. Stoof, E. Vliegen, U. Al Khawaja
We show that an antiferromagnetic spin-1 Bose-Einstein condensate, which can for instance be created with Na-23 atoms in an optical trap, has not only singular line-like vortex exc…
Kinetic Theory of Collective Excitations and Damping in Bose-Einstein Condensed Gases
U. Al Khawaja, H. T. C. Stoof
We calculate the frequencies and damping rates of the low-lying collective modes of a Bose-Einstein condensed gas at nonzero temperature. We use a complex nonlinear Schrödinger equ…
The Surface of a Bose-Einstein Condensed Atomic Cloud
U. Al Khawaja, C. J. Pethick, H. Smith
We investigate the structure and collective modes of a planar surface of a trapped Bose-Einstein condensed gas at zero temperature. In the long-wavelength limit we find a mode simi…