Real-time ESR lock-in magnetic imaging with NV-diamond

Electron spin resonance (ESR) lock-in sensing protocols with nitrogen vacancy (NV) centers in diamond allow for wide-field, real time imaging of magnetic fields for biological applications ranging from bio-current imaging to wide-field tracking of magnetic nano-particles. ESR lock-in NV measurements have previously been utilized for the optical detection of firing action potentials in giant axons [1]. By modulating the applied microwave driving field and imaging the NV fluorescence with a specialized lock-in camera, we are able to create real time videos of local magnetic fields with high spatial (~1 μm) and temporal (~1 ms) resolution over a large field of view (~1 mm). Here we show demonstrate a volume-normalized sensitivity of ~100 nT*μm^(3/2)*Hz^(−1/2) and compatibility with living biological systems. This work paves the way for the development of broadband quantum diamond microscopes for imaging bio-magnetic fields from neuronal activity.

References:
J. F. Barry, M. J. Turner, J. M. Schloss, D. R. Glenn, Y. Song, M. D. Lukin, H. Park, and R. L. Walsworth, Optical magnetic detection of single-neuron action potentials using quantum defects in diamond, Proc. Natl. Acad. Sci. 113, 14133 (2016).