Proposal for Quantum Sensing Based on Two-Dimensional Dynamical Decoupling: NMR Correlation Spectroscopy of Single Molecules

TL;DR

This paper introduces a universal two-dimensional dynamical decoupling scheme for quantum sensing, enabling correlation spectroscopy of single molecules in NMR by analyzing sensor coherence patterns under resonant conditions.

Contribution

It presents a novel two-dimensional DD-based quantum sensing method for correlation spectroscopy in single-molecule NMR, filling a gap in standard techniques.

Findings

Two-dimensional DD sequences can match different transition frequencies.

Sensor coherence patterns reveal nuclear spin correlations.

Method enables systematic correlation spectroscopy at the single-molecule level.

Abstract

Nuclear magnetic resonance (NMR) has enormous applications. Two-dimensional NMR is an essential technique to characterize correlations between nuclei and, hence, molecule structures. Towards the ultimate goal of single-molecule NMR, dynamical-decoupling- (DD) enhanced diamond quantum sensing enables the detection of single nuclear spins and nanoscale NMR. However, there is still the lack of a standard method in DD-based quantum sensing to characterize correlations between nuclear spins in single molecules. Here we present a scheme of two-dimensional DD-based quantum sensing, as a universal method for correlation spectroscopy of single molecules. We design two-dimensional DD sequences composed of two sets of periodic DD sequences with different periods, which can be independently set to match two different transition frequencies for resonant DD. We find that under the resonant DD condition the sensor coherence patterns, as functions of the two independent pulse numbers of DD subsequences, can fully determine different types of correlations between nuclear spin transitions. This work offers a systematic approach to correlation spectroscopy for single-molecule NMR.