Nanoscale Nuclear magnetic resonance with quantum sensors enhanced by nanostructures

Quantum sensors based on Nitrogen vacancy (NV) centers in diamond have demonstrated highly sensitive nanoscale detection of nuclear spins [1,2]. For the application in biochemistry, however, several challenges of the technique must be overcome. The spectral resolution achieved so far is low, mainly due to diffusion in liquid-state samples [3]. In addition to this the sample molecules and the sensor are typically not colocalized, which hinders practical application of the method. We overcome these limitations by fabricating nanostructures in diamond and trapping samples in them. We furthermore show the deterministic creation of NV centers within these nanostructures and characterize them by coherence measurements. To enhance the optical readout, we apply a single nuclear spin as a quantum memory. These improvements allow the nuclear magnetic resonance (NMR) detection of nanoconfined liquid-state samples.

[1] T. Staudacher et al. Science 339 (2013) 561

[2] H. Mamin et al. Science 339 (2013) 557

[3] N. Aslam et al. Science 357 (2017) 67