# Improving Resolution of Solid State NMR in Dense Molecular Hydrogen

## TL;DR

This paper demonstrates the first application of homo-nuclear Lee-Goldburg decoupling in solid state NMR at pressures above 100 GPa, significantly improving spectral resolution in dense molecular hydrogen.

## Contribution

It introduces a novel NMR decoupling technique under extreme conditions and employs Lenz lens resonators for homogeneous B1 fields in tiny sample cavities.

## Key findings

- Achieved 1600-fold narrowing of 1H resonance line-widths
- Demonstrated effective decoupling at pressures over 100 GPa
- Used Lenz lens resonators for homogeneous excitation

## Abstract

Recent advancements in radio-frequency resonator designs have led to the implementation of nuclear magnetic resonance in diamond anvil cells (DACs) at pressures well above 100 GPa. However, a relatively low resolution and the absence of decoupling sequences complicate the analysis of the results of solid state NMR in DACs. Here, we present the first application of homo-nuclear Lee-Goldburg (LG) decoupling at extreme conditions on high density molecular hydrogen. Lenz lens based two-dimensional resonator structures were found to generate a homogeneous B1 field across sample cavities as small as 12 picolitres, a prerequisite for optimal decoupling. At ideal LG conditions, the broad 1H resonance of molecular ortho-hydrogen was narrowed 1600-fold, resulting in line-widths of 3.1 ppm.