Force-detected nuclear double resonance between statistical spin polarizations

TL;DR

This paper demonstrates nuclear double resonance at the nanoscale using magnetic resonance force microscopy, revealing flip-flop interactions between spins driven by statistical polarization, and introduces a new cross-polarization technique for nanometer-scale magnetic resonance.

Contribution

It presents a novel cross-polarization method for statistical ensembles, enabling chemical contrast at nanometer scales in magnetic resonance imaging.

Findings

Observed flip-flops between 1H and 13C spins under Hartmann-Hahn condition

Coupling of spin fluctuations demonstrated in nanometer-scale samples

Developed a new cross-polarization technique for statistical spin ensembles

Abstract

We demonstrate nuclear double resonance for nanometer-scale volumes of spins where random fluctuations rather than Boltzmann polarization dominate. When the Hartmann-Hahn condition is met in a cross-polarization experiment, flip-flops occur between two species of spins and their fluctuations become coupled. We use magnetic resonance force microscopy to measure this effect between 1H and 13C spins in 13C-enriched stearic acid. The development of a cross-polarization technique for statistical ensembles adds an important tool for generating chemical contrast in nanometer-scale magnetic resonance.