Related papers: Phonon instability and self-organized structures i…
Experiments studying phonon mediated drag in the double layer two dimensional electron gas system are reported. Detailed measurements of the dependence of drag on temperature, layer spacing, density ratio, and matched density are discussed.…
We investigate the stability of dark solitons (DSs) in an effectively one-dimensional Bose-Einstein condensate in the presence of the magnetic parabolic trap and an optical lattice (OL). The analysis is based on both the full…
Properties of localized states on array of BEC confined to a potential, representing superposition of linear and nonlinear optical lattices are investigated. For a shallow lattice case the coupled mode system has been derived. The…
We analyze the physics of Bose-Einstein condensates confined in 2D quasi-periodic optical lattices, which offer an intermediate situation between ordered and disordered systems. First, we analyze the time-of-flight interference pattern that…
The development of integrated, waveguide-based atom optical devices requires a thorough understanding of nonlinear matter-wave mixing processes in confined geometries. This paper analyzes the stability of counterpropagating two-component…
We present a theoretical analysis of dilute gas Bose-Einstein condensates with dipolar atomic interactions under rotation in elliptical traps. Working in the Thomas-Fermi limit, we employ the classical hydrodynamic equations to first derive…
We experimentally show that dipolar interaction can stabilize otherwise unstable many-body systems like an attractive Bose gas. In a one dimensional lattice the repulsive dipolar on-site interaction balances negative scattering lengths up…
The behaviour of a harmonically trapped dipolar Bose-Einstein condensate with its dipole moments rotating at angular frequencies lower than the transverse harmonic trapping frequency is explored in the co-rotating frame. We obtain…
The propagation of solitons in dipolar BEC in a trap potential with a barrier potential is investigated. The regimes of soliton transmission, reflection and splitting as a function of the ratio between the local and dipolar nonlocal…
We systematically construct stationary soliton states in a one-component, two-dimensional, repulsive, Gross-Pitaevskii equation with a ring-shaped target-like trap similar to the potential used to confine a Bose-Einstein condensate in a…
In a benchmark dynamical-lattice model in three dimensions, the discrete nonlinear Schr{\"{o}}dinger equation, we find discrete vortex solitons with various values of the topological charge $S$. Stability regions for the vortices with…
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…
We study the equilibrium states of a vortex in a Bose-Einstein condensate in a one-dimensional optical lattice. We find that quantum effects can be important and that it is even possible for the vortex to be strongly squeezed, which…
While fundamental-mode discrete solitons have been demonstrated with both self-focusing and defocusing nonlinearity, high-order-mode localized states in waveguide lattices have been studied thus far only for the self-focusing case. In this…
By means of mean-field theory, we have studied the structure and excitation spectrum of a purely dipolar Bose gas in pancake-shaped trap where the confinement in the x-y plane is provided by a highly anharmonic potential resulting in an…
We study numerically the excitations of off-centered vortices in a Bose-Einstein condensate. The displacement of a single vortex and the separation of a doubly quantized vortex are considered. We find that the core-localized excitations of…
We consider a one-dimensional model of a two-component Bose-Einstein condensate in the presence of periodic external potentials of opposite signs, acting on the two species. The interaction between the species is attractive, while…
We report first principles calculations of the phonon dispersions of PbTe both for its observed structure and under compression. At the experimental lattice parameter we find a near instability of the optic branch at the zone center, in…
The Bogoliubov equations are solved for a three-dimensional Bose-Einstein condensate containing a doubly quantized vortex, trapped in a harmonic potential. Complex frequencies, signifying dynamical instability, are found for certain ranges…
We introduce an effectively one-dimensional (1D) model of a bosonic gas of particles carrying collinear dipole moments which are induced by an external polarizing field with the strength periodically modulated along the coordinate, which…