Ultrasensitive Magnetometry and Imaging with NV Diamond

NV centers in a diamond are proving themselves to be good building blocks for quantum information, electron spin resonance (ESR) imaging, and sensor applications. The key feature of the NV is that it has an electron spin that can be polarized and read out at room temperature. The readout is optical, thus the magnetic field imaging can also be done easily. Magnetic field variation with feature sizes below 0.3 microns cannot be directly resolved, and so in this region magnetic resonance imaging must be employed. To realize the full sensitivity of NV diamond, the spin transition linewidth must be as narrow as possible. Additionally, in the case of NV ensembles for micron-sized magnetometers, there must be a high concentration of NV. To this end three techniques are explored: (1) Electron paramagnetic resonance (EPR) imaging with microwave field gradients, (2) Magic angle rotation of magnetic field, and (3) TEM irradiation to optimize the yield of NV in a diamond.