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Dimensionality plays an important role in the physics of cold quantum
gases. For a one-dimensional (1D) system of repulsive bosons a
surprisingly rich variety of quantum regimes has been predicted,
including some regimes that do not exist in 3D.
Atom chips appear particularly well suited to realize atom waveguides and other (quasi-)1D structures. In this contribution the possibilities of reaching and detecting the above regimes on an atom chip are investigated. We address several issues that are relevant for creating and characterizing a 1D Bose gas. For instance, we demonstrate how one can create an axial box potential on a chip. Such a potential allows one to reach a much wider range of parameters than the much more usual harmonic confinement. Furthermore we discuss how one can circumvent the detection problems that arise in the regime of extremely low axial density. A scheme is exhibited that should allow the direct observation of the axial momentum distribution, even for such ultradilute clouds. A setup has been constructed that uses the mirror MOT technique in combination with current-carrying wires to cool and trap Rb atoms. We have built two types of microtraps: (i) a trap consisting of thin copper wires glued under a 0.2-mm thick mirror, combining flexibility and simplicity. (ii) lithographically patterned wire traps using gold evaporated in silicon. Our progress in trapping and cooling using these traps will also be reported at the conference. |