Modulational instability in Bose-Einstein condensates in optical lattices

Modulational Instability in Bose-Einstein Condensates under Feshbach Resonance Management

We investigate the modulational instability of nonlinear Schrödinger equations with periodic variation of their coefficients. In particular, we focus on the case of the recently proposed, experimentally realizable protocol of Feshbach Resonance Management for Bose-Einstein condensates. We derive the corresponding linear stability equation analytically and we show that it can be reduced to a Kro...

Bose-Einstein Condensates in Optical Quasicrystal Lattices

Producing Bose-Einstein condensates using optical lattices.

We relate the entropies of ensembles of atoms in optical lattices to atoms in simple traps. We then determine which ensembles of lattice-bound atoms will adiabatically transform into a Bose condensate. This shows a feasible approach to Bose condensation without evaporative cooling.

Modulational instability of two-component Bose-Einstein condensates in an optical lattice

We study modulational instability of two-component Bose-Einstein condensates in an optical lattice, which is modelled as a coupled discrete nonlinear Schrödinger equation. The excitation spectrum and the modulational instability condition of the total system are presented analytically. In the long-wavelength limit, our results agree with the homogeneous two-component Bose-Einstein condensates c...

Avalanches of Bose–Einstein condensates in leaking optical lattices

We study the decay of an atomic Bose–Einstein condensate (BEC) population N (τ ) from the leaking boundaries of an optical lattice (OL). For a rescaled interatomic interaction strength 3>3b, discrete breathers (DBs) are created that prevent the atoms from reaching the leaking boundaries. Collisions of other lattice excitations with the outermost DBs result in avalanches, i.e. steps in N (τ ), w...