Multiplexed scanning microscopy with dual-qubit spin sensors

TL;DR

This paper introduces a multiplexed scanning microscopy technique using dual-qubit NV centers that enables simultaneous imaging of multiple magnetic field components and two-point correlations at nanoscale resolution.

Contribution

It develops a novel multiplexed quantum sensing method with dual-NV centers, enhancing imaging capabilities and enabling measurement of complex spatial correlations.

Findings

Successfully demonstrated dual-NV magnetometry imaging multiple field projections.

Recorded two-point covariance of correlated field fluctuations across a wire.

Established a framework for investigating spatio-temporal correlations at nanoscale.

Abstract

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.