Optimal Sensing Protocol for Statistically Polarized Nano-NMR with NV Centers

TL;DR

This paper demonstrates that phase-sensitive protocols, especially quantum heterodyne detection, significantly improve nano-NMR spectroscopy with NV centers by maximizing information extraction and enabling resolution of chemical shifts and couplings at the nanoscale.

Contribution

It introduces an optimal sensing protocol using Fisher information to enhance nano-NMR with NV centers and provides the most accurate Qdyne detection experiments to date.

Findings

Phase-sensitive protocols outperform traditional methods in nano-NMR.

Optimal parameters for quantum heterodyne detection are derived.

Achieved the most accurate nano-NMR Qdyne detection experiments.

Abstract

Diffusion noise represents a major constraint to successful liquid state nano-NMR spectroscopy. Using the Fisher information as a faithful measure, we theoretically calculate and experimentally show that phase sensitive protocols are superior in most experimental scenarios, as they maximize information extraction from correlations in the sample. We derive the optimal experimental parameters for quantum heterodyne detection (Qdyne) and present the most accurate statistically polarized nano-NMR Qdyne detection experiments to date, leading the way to resolve chemical shifts and $J$ couplings at the nanoscale.