Related papers: Phase coherence and ``fragmented'' Bose condensate…
We discuss a possible link between the recently observed macroscopic ordering of ultra cold dipolar excitons (MOES) and the phenomenon of supersolidity. In the dilute limit we predict a stable supersolid state for a quasi-one-dimensional…
The realisation of Bose-Einstein condensation under grand-canonical conditions has provided the experimental evidence for the simultaneous occurrence of macroscopic fluctuations and phase coherence of the condensate. The observation of…
The Bose polaron is a quasiparticle that arises from the interaction between impurities and Bogoliubov excitation in Bose-Einstein condensates, analogous to the polaron formed by electrons and phonons in solid-state physics. In this paper,…
We experimentally and theoretically study phase coherence in two-component Bose-Einstein condensates of $^{87}{\rm Rb}$ atoms on an atom chip. Using Ramsey interferometry we measure the temporal decay of coherence between the…
We examine the phase evolution of a Bose-Einstein condensate of photons generated in a dye microcavity by temporal interference with a phase reference. The photo-excitable dye molecules constitute a reservoir of variable size for the…
We discuss Bose-Einstein condensation in a trapped gas of bosonic particles interacting dominantly via dipole-dipole forces. We find that in this case the mean-field interparticle interaction and, hence, the stability diagram are governed…
A Bose-Einstein condensate in an external potential consisting of a superposition of a harmonic and a random potential is considered theoretically. From a semi-quantitative analysis we find the size, shape and excitation energy as a…
We consider the precise quantum state of two trapped, coupled Bose Einstein condensates in the two-mode approximation. We seek a representation of the state in terms of a Wigner-like distribution on the two-mode Bloch sphere. The problem is…
We study condensation transitions in the steady state of a zero-range process with two species of particles. The steady state is exactly soluble -- it is given by a factorised form provided the dynamics satisfy certain constraints -- and we…
We investigate phase diffusion of a two-component Bose-Einstein condensates prepared initially in arbitrary coherent spin state $|\theta_0,\phi_0\rangle$. Analytical expression of the phase-diffusion time is presented for…
We examine the possibility of Bose-Einstein condensation in one-dimensional interacting Bose gas subjected to confining potentials of the form $V_{\rm ext}(x)=V_0(|x|/a)^\gamma$, in which $\gamma < 2$, by solving the Gross-Pitaevskii…
We discuss the dynamics of a Bose-Einstein condensate in a double-well trap subject to phase noise and particle loss. The phase coherence of a weakly-interacting condensate as well as the response to an external driving show a pronounced…
We show that there are three possible phases for a spin-2 spinor Bose condensate, one more compared to the spin-1 case. The order parameters of these phases are the spontaneous magnetization and the singlet pair amplitude. Current estimates…
We consider a multicomponent atomic Bose-Einstein condensate optically trapped in a far-off resonant dipole trap. Drawing an analogy with the optical situation, we show that this system can be regarded as an matter-wave analog of optical…
We study theoretically the interaction-induced generation of mesoscopic coherent spin state superpositions (small cat states) from an initial coherent spin state in bimodal Bose-Einstein condensates and the subsequent phase revival,…
When a Bose-Einstein condensate is divided into two parts, that are subsequently released and overlap, interference fringes are observed. We show here that this interference is typical, in the sense that most wave functions of the…
The ground state solutions of a dilute Bose condensate with contact and magnetic dipole-dipole interactions are examined. By lowering the value of the scattering length, Goral et al. [cond-mat/9907308 and Phys. Rev. A {\bf 61}, 051601…
A periodically kicked ring of a Bose-Einstein condensate is considered as a nonlinear generalization of the quantum kicked rotor. For weak interactions between atoms, periodic motion (anti-resonance) becomes quasiperiodic (quantum beating)…
We study a two-dimensional system of bosons interacting with a fluctuating U(1) gauge field with overdamped dynamics. We find two instabilities of the condensed phase at T=0: one to phase separation and another to a homogeneous…
The temporal coherence of an ideal Bose gas increases as the system approaches the Bose-Einstein condensation threshold from below, with coherence time diverging at the critical point. However, counter-examples have been observed for…