Related papers: Collisional relaxation in diffuse clouds of trappe…
We determine the leading shift of the Bose-Einstein condensation temperature for an ultracold dilute atomic gas in a harmonic trap due to weak disorder by treating both a Gaussian and a Lorentzian spatial correlation for the quenched…
We theoretically investigate collective modes of a one-dimensional (1D) interacting Bose gas in harmonic traps at finite temperatures, by using a variational approach and local density approximation. We find that the temperature dependence…
Trapped bosonic atoms can be cooled down to temperatures where the atomic cloud experiences Bose-Einstein condensation. Almost all atoms in a dilute gaseous system can be Bose-condensed, which implies that this system is in a coherent…
We calculate the spectrum of low-lying collective excitations in a gaseous cloud formed by a Bose-Einstein condensate and a spin-polarized Fermi gas over a range of the boson-fermion coupling strength extending from strongly repulsive to…
By including the contribution of the thermal cloud to the Lagrangian of the condensate of a Bose gas, we extend the time-dependent variational method at zero temperature to study temperature-dependent low collective excitation modes. A…
We present a detailed study of the temperature dependence of the condensate and noncondensate density profiles of a Bose-condensed gas in a parabolic trap. These quantitites are calculated self-consistently using the Hartree-Fock-Bogoliubov…
We experimentally study the energy-temperature relationship of a harmonically trapped Bose-Einstein condensate by transferring a known quantity of energy to the condensate and measuring the resulting temperature change. We consider two…
We present predictions for the frequencies of collective modes of trapped Bose-condensed $^{87}$Rb atoms at finite temperature. Our treatment includes a self-consistent treatment of the mean-field from finite-$T$ excitations and the…
An ultra-cold Bose gas of two-level atoms can be thought of as a spin-1/2 Bose gas. It supports spin-wave collective modes due to the exchange mean field. Such collective spin oscillations have been observed in recent experiments at JILA…
Dipole oscillation is studied in a normal phase of a trapped Bose--Fermi-mixture gas composed of single-species bosons and single-species fermions. Applying the moment method to the linearized Boltzmann equation, we derive a closed set of…
We discuss certain specific features of the calculation of the critical temperature of a dilute repulsive Bose gas. Interactions modify the critical temperature in two different ways. First, for gases in traps, temperature shifts are…
This article describes experiments performed with an ultracold gas of metastable helium above the Bose-Einstein transition. The gas is trapped in an harmonic magnetic potential and collective excitations are induced. Both the frequency and…
We study the damping of low-lying collective excitations of condensates in a weakly interacting Bose gas model within the framework of imaginary time path integral. A general expression of the damping rate has been obtained in the low…
We discuss pair interatomic collisions in a Bose gas tightly confined in one (axial) direction and identify two regimes of scattering. In the quasi2D regime, where the confinement frequency $\omega_0$ greatly exceeds the gas temperature…
We study a Bose-condensed gas at finite temperature, in which the particles of the condensate and of the thermal cloud are constrained to move in a plane under radial harmonic confinement and interact via strictly two-dimensional…
The dynamics of Josephson-like oscillations between two coupled Bose-Einstein condensates is studied using the time-dependent variational method. We suppose that the quantum state of the condensates is a gaussian wave-packet which can…
A finite thermal anisotropy, if maintained for times longer than thermal relaxation times, may have a positive effect on the critical temperature in Bose-Einstein condensation of a dilute boson gas not in thermal equilibrium or…
We study transverse radial oscillations of an elongated Bose-Einstein condensate using finite temperature simulations, in the context of a recent experiment at ENS. We demonstrate the existence of a mode corresponding to an in-phase…
We provide an overview of the effects of interactions in Bose-condensed gases. We focus on phenomena that have been explored in ultracold atom experiments, covering both tuneable contact interactions and dipolar interactions. Our discussion…
A simple picture describes the results of recent treatments of partially-condensed, dilute, trapped Bose gases at temperature T > 0. The condensate wavefunction is nearly identical to that of a T=0 condensate with the same number of…