Advances in Magnetic Resonance Force Microscopy

Over the years magnetic resonance techniques have demonstrated to be powerful structural characterization and diagnostic imaging tools that have had a profound impact in medicine, biology, chemistry, material science and physics. While NMR provides the ability to perform molecular structure determination by investigating the local surroundings of atoms and the binding characteristics of molecules when placed in a homogeneous magnetic field, MRI provides three-dimensional visualization of subsurface structures when placed in a magnetic field gradient. The strengths of magnetic resonance techniques are numerous, however when applied to the microscale, they suffer notoriously by the lack of sensitivity of the conventional Faraday detection method and the availability of strong magnetic field gradients. Different approaches have been tried to improve the sensitivity of magnetic resonance techniques. In 1991 John Sidles of the U. of Washington proposed using mechanical detection of spin signals and small magnetic particles to create strong magnetic field gradients as a means of improving sensitivity and spatial resolution in magnetic resonance techniques with the potential and ultimate goal being the detection of a single nuclear spin. As proposed, such technique among other things could elucidate the structure of a single copy of a large bio-molecule, initialize and read the spin states of a quantum computer or probe the conduction states of a spintronic device. Despite the tremendous achievements in the field a lot of work remains to be done in order to make MRFM into a turnkey instrument to be placed in the hands of the biomedical community. We will present the current state of the field and our experiments along this endeavor.