Atom chips:: Fabrication and thermal properties

Neutral atoms can be trapped and manipulated with surface mounted microscopic current carrying and charged structures. We present a lithographic fabrication process for such atom chips based on evaporated metal films. The size limit of this process is below 1 mum. At room temperature, thin wires can carry current densities of more than 10(7) A/cm(2) and voltages of more than 500 V. Extensive test measurements for different substrates and metal thicknesses (up to 5 mum) are compared to models for the heating characteristics of the microscopic wires. Among the materials tested, we find that Si is the best suited substrate for atom chips. (C) 2004 American Institute of Physics.