Proposed high Q nanocantilever force sensor actuated by the Lorentz force acting on an integrated superconducting nanoinductor.

Annunziata et al.[1] have developed and characterized superconducting nanoinductors which are fabricated on sapphire substrates using standard processes. These nanoinductors consist of Nb or NbN wires on the order of 100 nm wide folded into serpentine layouts. The inductances below the critical temperature are of order 1 nH um -1 . It is proposed here to integrate these nanoinductors rather on a silicon on insulator (SOI) substrate. Standard SOI processing, including the backside, can be used to form the nanoinductors on the free end of a cantilever. Wiring and transmission lines are easily formed for connections DC and RF sources and monitoring outputs. Used as an AFM, force sensing is straightforward. In operation, the cantilever devices are subjected to a DC magnetic field, B, oriented along the length axis. Imposing DC and RF currents actuate mechanical oscillation via the Lorentz force. Both RF and mechanical Q will be higher in the superconducting state. Interesting new physics should emerge related to sensing above and below the critical field and/or the critical B field. [1] Anthony Annunziata et arXiv:1007.4187