Imaging nuclear spins weakly coupled to a probe paramagnetic center

TL;DR

This paper introduces a novel method for determining the spatial positions of weakly coupled nuclear spins using nitrogen-vacancy centers in diamond, enabling high-resolution nanoscale metrology without external magnetic field gradients.

Contribution

The authors propose a new strategy leveraging spin polarization flow for spatial localization of nuclear spins, avoiding the need for magnetic field gradients.

Findings

High spatial resolution achievable depending on NV lifetime and target spin location

No external magnetic field gradient required simplifies instrumentation

Method applicable to pinpoint other paramagnetic centers or study molecular dynamics

Abstract

Optically-detected paramagnetic centers in wide-bandgap semiconductors are emerging as a promising platform for nanoscale metrology at room temperature. Of particular interest are applications where the center is used as a probe to interrogate other spins that cannot be observed directly. Using the nitrogen-vacancy center in diamond as a model system, we propose a new strategy to determining the spatial coordinates of weakly coupled nuclear spins. The central idea is to label the target nucleus with a spin polarization that depends on its spatial location, which is subsequently revealed by making this polarization flow back to the NV for readout. Using extensive analytical and numerical modeling, we show that the technique can attain high spatial resolution depending on the NV lifetime and target spin location. No external magnetic field gradient is required, which circumvents complications resulting from changes in the direction of the applied magnetic field, and considerably simplifies the required instrumentation. Extensions of the present technique may be adapted to pinpoint the locations of other paramagnetic centers in the NV vicinity or to yield information on dynamical processes in molecules on the diamond surface.