We propose a new approach to measuring persistent currents in normal metal rings. By integrating micron-scale metal rings into sensitive micromechanical cantilevers and using the cantilevers as torque magnetometers, it should be possible to measure the rings' persistent currents with greater sensitivity than the SQUID-based and microwave resonator-based detectors used in the past. In addition, cantilever-based detectors may allow for measurements in a cleaner electromagnetic environment. We have fabricated ultra sensitive cantilevers with integrated rings and measured their mechanical properties. We present an estimate of the persistent current sensitivity of these cantilever-based detectors, focusing on the limits set by the cantilever's Brownian motion and the shot noise in the laser interferometer that monitors the cantilever.
@article{arxiv.0710.5259,
title = {High sensitivity cantilevers for measuring persistent currents in normal metal rings},
author = {Ania C. Bleszynski Jayich and Will E. Shanks and Rob Ilic and J. G. E. Harris},
journal= {arXiv preprint arXiv:0710.5259},
year = {2009}
}