A Fourier optics approach can be a concise and powerful tool to solve problems in atom optics. In this report, we adopt it to investigate the kinetic behavior of cold atoms passing through a far red-detuned Gaussian beam. We demonstrate that the aberration has significant influence on the evolution of the atomic cloud, which is rooted in the deviation of the Gaussian profile from the quadratic form. In particular, we observe an intriguing effect analogous to Fresnel＇s double prism with cold atoms, The experimental results are in good agreement with the numerical simulation.
Due to its low sensitivity to blackbody radiation, neutral mercury is a good candidate for the most accurate optical lattice clock. Here we report the observation of cold mercury atoms in a magneto-optical trap （MOT）. Because of the high vapor pressure at room temperature, the mercury source and the cold pump were cooled down to 40℃ and 70 ℃, respectively, to keep the science chamber in an ultra-high vacuum of 6×10^-9 Pa. Limited by the power of the UV cooling laser, the one beam folded MOT configuration was adopted, and 1.5×10^5 Hg-202 atoms were observed by fluorescence detection.
We derive the coupled nonpolynomial nonlinear Schr6dinger equations for a two-component Bose-Lmstem conaensate in a quasi-one-dimension geometry and investigate the effects of a tightly transverse trapping on the ground state and the miscibility-immiscibility threshold. We find that the density profile of the matter wavepacket is remarkably dependent on the transverse width and the effective one-dimension nonlinear coupling strengths in miscible and immiscible regimes.
We theoretically investigate quantum phases and transport dynamics of ultracold atoms trapped in an optical lattice in the presence of effective multi-body interaction. When a harmonic external potential is added, several interesting phenom- ena are revealed, such as the broadening and the emergence of a central insulator plateau and the phase transition between superftuid and Mott insulator phase. We also study the transport of the system which runs across the superfluid-insulator transition after ramping up the lattice, and predict a slower relaxation which is attributed to the influence of the multi-body interaction on the mass transport.
Interaction between Rydberg atoms can be used to control the properties of interatomic interaction in ultracold gases by weakly dressing the atoms with a Rydberg state. Here we investigate the effect of the Rydberg-dressing interaction on the ground-state properties of a Bose–Einstein condensate imposed by Raman-induced spin–orbit coupling. We find that,in the case of SU（2）-invariant s-wave interactions, the gas is only in the plane-wave phase and the zero-momentum phase is absent. In particular, we also predict an unexpected magnetic stripe phase composed of two plane-wave components with unequal weight when s-wave interactions are non-symmetric, which originates from the Rydberg-dressing interaction.
We investigate the transport dynamics of an interacting binary Bose-Einstein condensate in an incommensurate optical lattice and predict a novel splitting of a matter wavepacket induced by disorder potential and inter-species interaction. The effect of atomic interaction on the dynamics of the mobile and localized atoms are also studied in detail. We also discuss the behavior of the balanced and inbalanced mixtures in the incommensurate optical lattice.
