Nanometer-Scale Force-Detected Nuclear Magnetic Resonance Imaging
Technical Report,13 Aug 2012,12 Aug 2016
University of Illinois at UrbanaChampaign Champaign United States
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The goal of the proposed research program is to develop fundamentally new approaches in force detected magnetic resonance techniques and achieve nanometer-scale nuclear spin imaging. During the past several years, our group has pursued this goal using silicon nanowire SiNW resonators for force detection. The ultralow mechanical dissipation inherent in SiNW resonators is ideally suited for detecting sub-attonewton-scale forces. Recently, we have used radio frequency RF SiNW resonators to detect proton spins in polystyrene with a near thermally limited force sensitivity of 1.9 aN2Hz this result represents a significant improvement in sensitivity over previous published MRFM data. To achieve this result, we developed a new spin detection protocol which uses time-dependent magnetic field gradients, generated by passing electric currents through a narrow metallic constriction, to achieve efficient coupling between nuclear spins and an RF mechanical resonator. The ability to generate time dependent field gradients opens the possibility for applying well-established Fourier encoding techniques for efficient MRFM imaging.
- Atomic and Molecular Physics and Spectroscopy