Diffusion restricted nano nmr using nitrogen vacancy centers in diamond.

Nano-NMR spectroscopy with nitrogen-vacancy centres is a promising platform to perform NMR from tiny sample volume. Realizing non-polarized Nano-NMR requires probing the signal, induced by the statistical polarization in such a small sample volume. The magnetic field generated by the latter is detected via the NV electron spin by measuring its spin state optically. As the nuclei in the sample diffuse out of the detection volume, the correlation of the signal decays, limiting the amount of information that can be extracted about the sample. The decay limits the measurement time to the characteristic diffusion time of the sample molecules through the detection volume and reduces the resolution. This effect of diffusion can be mitigated by spatially confining a small sample volume(1).We investigate experimentally several approaches for confining the liquids in nano pots created at the diamond surface for the purpose of improved resolution.