Magnetic Resonance Spectroscopy using Quantum Defects in Diamond
Abstract: Magnetic resonance (MR) measures chemical and magnetic properties and is the foundation of non-invasive detection techniques such as magnetic resonance imaging (MRI). Applied at the nanoscale, magnetic resonance would be capable of imaging the structure of biomolecules and of manipulating and characterizing magnetic device components. However, achieving MR with high spatial resolution is challenging due to the inherent weakness of spin coupling to inductive probes. Quantum defects in wide-band gap or insulating materials have thus attracted much attention for their atomic size and their ultrasensitive detection of magnetic fields. In this talk, I will introduce nitrogen-vacancy (NV) centers and their uses as room-temperature magnetic field probes. I will present our recent results on NV-based, off-resonant detection of paramagnetic and ferromagnetic resonance spectra. The sensitivity of NV centers to incoherent dynamics has varied uses. In the case of paramagnetic target spins, our off-resonant technique points to an easily implementable approach to using bright, biocompatible nanodiamonds as in vivo probes. In the case of ferromagnetic target spins, field noise due to thermally excited spinwaves will determine the feasibility of coherent coupling between defect spins and spinwaves, a proposed hybrid platform for quantum technologies.