Discriminating nuclear spins in an electronic environment over several nanometers and several hundred nuclei*

Controlling and discriminating nuclear spins in an electronic spin environment is a key to several applications including for quantum registers, memories, and sensors constructed out of nuclear spins. Typically however, there is a limited possibility of spatially distinguishing the spins, other than a small shell where the nuclear resonance frequencies can be significantly shifted from those of the bulk. Previous nanoscale quantum sensing experiments have, for instance, been limited to proximal central spin relaxation effects in small (<20) spin networks. In this work, we experimentally demonstrate a new method to discriminate nuclear spins surrounding an electron spanning several nanometers and involving several hundred nuclei. Our approach involves a novel means of symmetry-breaking of a Floquet Hamiltonian that originally leads to prethermalization of the nuclear polarization, but which is now locally symmetry broken on action of nanoscale gradient from the electronic hyperfine field. This enables the simple ability to discriminate different nuclear “shells” by tracking the polarization spin diffusion dynamics. We demonstrate this experimentally in a model system of ¹³C nuclear spins surrounding an NV center electron in diamond. Applications to spatially resolved quantum sensing, and the ability to rewritably engineer spin polarization texture into these nuclei will be discussed.