Mapping single electron spins with magnetic tomography

TL;DR

This paper introduces a magnetic tomography technique using a nitrogen-vacancy center in diamond to precisely locate single electron spins with sub-angstrom accuracy, enabling nanoscale magnetic resonance imaging.

Contribution

The novel method employs rotating magnetic fields to modulate dipolar coupling, allowing accurate position mapping of electron spins near quantum sensors.

Findings

Achieved 0.9 Å positional uncertainty for electron spins

Located spins up to 10 nm away from the sensor

Applicable to mapping hyperfine coupled spins and radicals

Abstract

Mapping the positions of single electron spins is a highly desired capability for applications such as nanoscale magnetic resonance imaging and quantum network characterization. Here, we demonstrate a method based on rotating an external magnetic field to identify the precise location of single electron spins in the vicinity of a quantum spin sensor. We use a nitrogen-vacancy center in diamond as a quantum sensor and modulate the dipolar coupling to a proximate electron spin in the crystal by varying the magnetic field vector. The modulation of the dipolar coupling contains information on the coordinates of the spin, from which we extract its position with an uncertainty of 0.9\,\AA. We show that the method can be used to locate electron spins with nanometer precision up to 10\,nm away from the sensor. We discuss the method's applicability to mapping hyperfine coupled electron spins, and show it may be applied to locating nitroxide radicals. The magnetic tomography method can be utilized for distance measurements for studying the structure of individual molecules.