The Atom Chip
Trinker, M., Groth, S., Haslinger, S., Manz, S., Betz, T., Schneider, S., Bar-Joseph, I., Schumm, T. & Schmiedmayer, J.
Multilayer atom chips for versatile atom micromanipulation
Applied Physics Letters, 2008, Vol. 92(25), pp. 254102
The central part of the experimental setup is the atom chip and the surrounding assembly. With the exception of small homogeneous external bias fields, all trapping fields in our experiments are provided by the chip itself or by the copper structures mounted directly underneath. This necessitates independent electrical access to as many as 45 different contact points inside the vacuum chamber; eight of these connections need high current tolerances of 50–100A (the others only up to 2A). The resulting complex construction of various UHV-compatible ceramics and metal holders, copper connectors, special alloy pins, isolating Kapton foils etc. consists of several hundred custom made pieces.
SEM micrograph of the central part of a multilayer chip. 10 µm wide wires with a height of 1.4 µm cross structures created by e-beam lithography. The smallest features are 300 nm gaps between 700 nm wide and 140 nm high wires. Electrical insulation of the two layers is provided by 500 nm thick polyimide pads, visible as partially transparent layer.