Magnetic Guiding Of Atoms With Current-carrying Conductors And Its Atom-optical Elements

The research background of atomic guiding and its recent development are reviewed. The guiding, control and manipulation of neutral atoms rely on the interactions of magnetic fields (or light fields) with neutral atoms. Various schemes of atomic guiding are classified and some applications of atom-guiding technology are introduced. We also introduce atomic beam splitter in details, which is one of important elements of atom optics.We propose two novel schemes to guide cold neutral atoms by using a static magnetic field from a V- and U-shaped current-carrying conductors (VCCC and UCCC). In the scheme of the VCCC, we calculate the relationships between the distributions of the magnetic field along z-axis or x-direction and various parameters of the VCCC, and obtain several fitting equations that can be used to describe the relationships mentioned above. We also investigate the relationships between the magnetic force exerting on the guided atoms and the parameters of the VCCC. Moreover, we propose some atom-optical elements based on the VCCC, such as atomic funnel, atomic beam splitter and atomic interferometer. In the scheme of the UCCC. we calculate the relationships between the distribution of the magnetic field and the parameters of the UCCC. We find that the UCCC can be used to realize both single- and double-channel magnetic guiding of cold atoms. The number of guiding channel is determined by the shape parameter B = b/a, whose critical value is 0.5389. In the case of single-channel magnetic guiding, we calculate the relationship between the guiding efficiency and electric current or the transverse temperature of atomic beam. We also propose several atom-optical elements base on the UCCC.We propose a novel controllable atomic beam-spiller based on the UCCC and discuss the splitting mechanism of the guided atomic beam in the beam splitter from two aspects of the magnetic-field distribution and the trace of the guiding centers. The splitting ratio of the beam splitter can be adjusted by adding a homogeneous bias magnetic field along the y-direction, and the relationship between the splitting ratioand the additional bias field is analyzed. By using the classical Monte-Carlo method, the splitting process of the guided atomic beam in the beam splitter is simulated, and the transverse adiabatic cooling and heating effects of the atomic beam in the beam splitter are simulated and analyzed from a simple theoretical model.In the case of non-interacting and interacting between the guided atoms, we use the Schrodinger equation of cold atoms in single-channel magnetic guide to obtain the solutions of atomic wave function, and calculate the size of the ground-state wave function in the case of non-interacting between cold atoms. In the scheme of the atomic interferometer based on the UCCC, we discuss the approximate solution of atomic matter wave-function in double-channel magnetic guide, and analyze the evolution of transverse wave function in the process of atomic interference and show the probability distribution after the interference. Finally, we present the approximate distribution of trapping potential of the guided cold atoms in the atomic funnel based on the VCCC or the UCCC. By using a similar method in the analysis of optical coherence, we study the coherent evolution of the ground-state wave function of ultra-cold atoms in atomic funnel, and obtain some normalized correlation functions of the first, second, third and high order.