Efficient route to high-bandwidth nanoscale magnetometry using single spins in diamond

Area of Science:

• Quantum Metrology
• Nanoscale Sensing
• Spectroscopy

Background:

• Nitrogen-vacancy (NV) centers in diamond are versatile quantum sensors for magnetic fields, electric fields, and temperature at the nanoscale.
• NV centers offer Heisenberg scaling (σB ∝ 1/T) for precision, surpassing the shot-noise limit (σB = √T), particularly with phase estimation algorithms (PEAs).
• PEAs are limited to single frequencies and struggle with fluctuating or multifrequency signals, hindering applications like nanoscale Nuclear Magnetic Resonance (NMR).

Purpose of the Study:

• To develop an alternative precision magnetometry method for multifrequency signals.
• To adapt compressive sensing (CS) techniques for nanoscale NMR spectroscopy.
• To improve sensitivity and reduce resource requirements for quantum sensing of complex signals.

Main Methods:

• Proposed a novel method utilizing compressive sensing (CS) for precision magnetometry.
• Applied CS techniques to analyze frequency-multiplexed signals, specifically targeting nanoscale NMR.
• Demonstrated the method using model solid-state spectra of Glycine acquired under Magic Angle Spinning (MAS) conditions.

Main Results:

• Achieved precision scaling approximately as σB ≈ 1/T, approaching Heisenberg scaling for multifrequency signals.
• Demonstrated a 5-fold increase in sensitivity through dynamic-range gain.
• Showcased CS's ability to reduce the total number of resources required for sensing.

Conclusions:

• Compressive sensing (CS) offers a viable alternative to PEAs for precision magnetometry in complex, multifrequency environments.
• The proposed CS method enhances sensitivity and efficiency for nanoscale NMR and potentially other multifrequency sensing applications.
• This advancement broadens the applicability of NV-center-based quantum sensors to more complex molecular systems.