Adjustable microchip ring trap for cold atoms and molecules

摘要

We describe the design and function of a circular magnetic waveguide producedfrom wires on a microchip for atom interferometry using deBroglie waves. Theguide is a two-dimensional magnetic minimum for trapping weak-field seekingstates of atoms or molecules with a magnetic dipole moment. The design consistsof seven circular wires sharing a common radius. We describe the design, thetime-dependent currents of the wires and show that it is possible to form acircular waveguide with adjustable height and gradient while minimizingperturbation resulting from leads or wire crossings. This maximal area geometryis suited for rotation sensing with atom interferometry via the Sagnac effectusing either cold atoms, molecules and Bose-condensed systems.