@article{HenkelKruegerFolmanetal.2003, author = {Henkel, Carsten and Kr{\"u}ger, P. and Folman, R. and Schmiedmayer, J{\"o}rg}, title = {Fundamental limits for coherent manipulation on atom chips}, issn = {0946-2171}, year = {2003}, language = {en} } @article{FolmanKruegerSchmiedmayeretal.2002, author = {Folman, R. and Kr{\"u}ger, P. and Schmiedmayer, J{\"o}rg and Denschlag, J. H. and Henkel, Carsten}, title = {Microscopic atom optics : from wires to an atom chip}, year = {2002}, abstract = {We review the 10 year long journey into the miniaturization and integration of matter wave optics resulting in devices mounted on surfaces, so called atom chips. The first experiments started with the guiding of atoms with free standing wires and investigated the trapping potentials in simple geometries. Atom optical elements can now be micro fabricated down to 1 um size on atom chips. The creation of a Bose-Einstein condensate miniaturized in surface traps was recently achieved, and the first attempts to integrate light optics are in progress. In this review, we describe microscopic atom optics elements using current carrying and charged structures. Experiments with free standing structures (atom wires)are reviewed, investigating the basic principles of microscopic atom optics. We then discuss the miniaturization on the atom chip. One of the open central questions is dealt with: what happens with cold atoms close to a warm surface, how fast will they heat up or lose their coherence? The review concludes with an outlook of what we believe the future directions to be, and what can be hoped for.}, language = {en} } @article{HenkelNestDomokosetal.2004, author = {Henkel, Carsten and Nest, Mathias and Domokos, P. and Folman, R.}, title = {Optical discrimination between spatial decoherence and thermalization of a massive object}, year = {2004}, abstract = {We propose an optical ring interferometer to observe environment-induced spatial decoherence of massive objects. The object is held in a harmonic trap and scatters light between degenerate modes of a ring cavity. The output signal of the interferometer permits to monitor the spatial width of the object's wave function. It shows oscillations that arise from coherences between energy eigenstates and that reveal the difference between pure spatial decoherence and that coinciding with energy transfer and heating. Our method is designed to work with a wide variety of masses, ranging from the atomic scale to nanofabricated structures. We give a thorough discussion of its experimental feasibility}, language = {en} } @article{DikovskyJaphaHenkeletal.2005, author = {Dikovsky, V. and Japha, Y. and Henkel, Carsten and Folman, R.}, title = {Reduction of magnetic noise in atom chips by material optimization}, year = {2005}, abstract = {We discuss the influence of the material type in metal wires to the electromagnetic fluctuations in magnetic microtraps close to the surface of an atom chip. We show that significant reduction of the magnetic noise can be achieved by replacing the pure noble metal wires with their dilute alloys. The alloy composition provides an additional degree of freedom which enables a, controlled reduction of both magnetic noise and resistivity if the atom chip is cooled. In addition, we provide a careful re-analysis of the magnetically induced trap loss observed by Yu-Ju Lin et al. [Phys. Rev. Lett. 92 050404 (2004)] and find good agreement with an improved theory}, language = {en} }