Scanning probe microscopy with multi-qubit sensors offers the potential to improve imaging speed and measure previously inaccessible quantities, such as two-point correlations. We develop a multiplexed quantum sensing approach with scanning probes containing two nitrogen-vacancy (NV) centers at the tip apex. A shared optical channel is used for simultaneous qubit initialization and readout, while phase- and frequency-dependent microwave spin manipulations are leveraged for de-multiplexing the optical readout signal. Scanning dual-NV magnetometry is first demonstrated by simultaneously imaging multiple field projections of a ferrimagnetic racetrack device. Then, we record the two-point covariance of spatially correlated field fluctuations across a current-carrying wire. Our multiplex framework establishes a method to investigate a variety of spatio-temporal correlations, including phase transitions and electronic noise, with nanoscale resolution.
@article{arxiv.2407.19576,
title = {Multiplexed scanning microscopy with dual-qubit spin sensors},
author = {William S. Huxter and Federico Dalmagioni and Christian L. Degen},
journal= {arXiv preprint arXiv:2407.19576},
year = {2025}
}