The quantized vortex state is investigated in a Bose-Einstein condensate, confined in a multiply connected geometry formed by a Laguerre-Gaussian optical trap. Solving the Gross-Pitaevskii equation variationally, we show that the criterium for vortex stability is that the interatomic interaction strength must exceed a critical interaction strength. The time evolution of a freely expanding Lague...

We study the effect of Anderson localization on the expansion of a Bose-Einstein condensate, released from a harmonic trap, in a 3D random potential. We use scaling arguments and the self-consistent theory of localization to show that the long-time behavior of the condensate density is controlled by a single parameter equal to the ratio of the mobility edge and the chemical potential of the con...

The interactions responsible for Feshbach resonances in binary atom collisions produce a condensate of molecules in the atomic BEC-system. We discuss the ‘ground state’ of the condensate system and illustrate that its properties differ quantitatively and qualitatively from the properties of a single condensate with atom-atom interactions described by the effective scattering length that charact...

We analyze coherent two-color photoassociation of a Bose-Einstein condensate, focusing on stimulated Raman adiabatic passage (STIRAP) in free-bound-bound transitions from atoms to molecules. This problem raises an interest because STIRAP has been predicted to be absent in the nondegenerate case [Javanainen and Mackie, Phys. Rev. A 58, R789 (1998)]. Nevertheless, we find that Bose stimulation en...

A relaxation method is employed to study a rotating dense Bose-Einstein condensate beyond Thomas-Fermi approximation. We use a slave-boson model to describe the strongly interacting condensate and derive a generalized non-linear Schrödinger equation with kinetic term for the rotating condensate. In comparison with previous calculations, based on Thomas-Fermi approximation, significant improveme...

Based on the quark propagator in the instanton dilute liquid approximation, we calculate analytically the quark condensate < q̄q >, the mixed quark gluon condensate gs < q̄Gμνσ q > and the four quark condensate < q̄Γqq̄Γq > at the mean field level in the framework of global color symmetry model. The numerical calculation shows that the values of these condensates are compatible with the ranges dete...

class InteractiveIO { public InteractiveIO() { } public void write(String s) { System.out.println(s); System.out.flush(); } public String promptAndRead(String s) throws Exception { System.out.println(s); System.out.flush(); BufferedReader br; br = new BufferedReader(new InputStreamReader(System.in)); String line; line = br.readLine(); return line; } } 151 Verbessern der Implementierung von Inte...

We study the tunneling properties of a cigar-shaped Bose-Einstein condensate by using an effective 1D nonpolynomial nonlinear Schrödinger equation (NPSE). First we investigate a mechanism to generate periodic pulses of coherent matter by means of a Bose condensate confined in a potential well with an oscillating height of the energy barrier. We show that is possible to control the periodic emis...

Production of prostacyclin by endothelial cells is considered to be important in rendering the vessel wall nonthrombogenic. Cigarette smoking is an important risk factor in the pathogenesis of atherosclerosis. Here we show that the incubation of cultured human endothelial cells with a cigarette smoke condensate impaired the basal prostacyclin release. Also, the enhanced release of prostacyclin ...

We derive variationally the HFB equations for a trapped self-interacting Bose gas at finite temperature. In the Thomas-Fermi limit, we obtain simple expressions for the condensate, the non condensate and the anomalous densities. Their behavior in terms of the condensate fraction meets qualitatively the experimental data. In particular, the non condensate and the anomalous densities are peaked a...