Integrated Cantilever Loop Probe for Magnetic Resonance Force Microscopy

The measurement of magnetic fields, especially at the nanoscale, has become an issue of considerable interest. Applications include quantum computing, data storage, and magnetic resonance imaging (MRI). At the interface between conventional atomic force microscopy and MRI lies magnetic resonance force microscopy. Radio frequency (RF) waves excite electrons in a sample, and a magnetic cantilever probe can image a slice of the sample in which the electron resonance is altered by the probe field. We have fabricated a novel probe that incorporates the RF loop onto the cantilever itself, allowing sensitive spatial resolution. While single-electron imaging has recently been accomplished [1], our goal is to produce a more robust system based on readily accessible technology. The probe loop is composed of 250 nm thick Au, patterned to include shielding and coaxial contact pads. The cantilever is etched from high-resistivity single-crystal Si using DRIE. We present proof of theory, along with simulations of magnetic and electrical fields. [1] D. Rugar et al. Nature Vol. 430, p. 329 (2004)