Nuclear magnetic resonance spectroscopy with single spin sensitivity.

Area of Science:

• Quantum sensing
• Atomic physics
• Solid-state physics

Background:

• Achieving ultimate sensitivity in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) necessitates novel detection strategies.
• The strong coupling regime, where sensor-sample spin interactions dominate, offers a pathway beyond classical limits.
• This regime permits detection of unpolarized nuclei, surpassing reliance on statistical magnetization fluctuations.

Purpose of the Study:

• To demonstrate a new NMR detection strategy based on strong coupling.
• To achieve single nuclear spin sensitivity and imaging under ambient conditions.
• To push the boundaries of NMR/MRI sensitivity for single-molecule and single-spin applications.

Main Methods:

• Utilizing strong coupling between an atomic nitrogen-vacancy (NV) center in diamond and sample nuclear spins.
• Performing nuclear magnetic resonance on four silicon-29 ((29)Si) nuclear spins.
• Exploiting the NV sensor's generated magnetic field gradient combined with compressed sensing for imaging.

Main Results:

• Successfully demonstrated strong coupling between an NV sensor and (29)Si nuclear spins.
• Achieved nuclear magnetic resonance on individual (29)Si nuclear spins.
• Realized imaging protocols with angstrom-level precision for individual nuclei.
• Attained single nuclear spin sensitivity within seconds under ambient conditions.

Conclusions:

• Strong coupling provides a viable strategy for ultra-sensitive NMR and MRI.
• Diamond NV centers can serve as sensitive probes for single nuclear spin detection and imaging.
• This technique opens new avenues for nanoscale sensing and materials characterization.