Dependence of nuclear spin singlet lifetimes on RF spin-locking power

TL;DR

This study investigates how RF spin-locking power affects nuclear spin singlet lifetimes, demonstrating that long-lived states can be maintained with significantly lower RF power, which has implications for in vivo biomolecular studies.

Contribution

The paper introduces a simple theoretical model that accurately predicts singlet lifetime dependence on RF power, including low-power regimes, and shows that long-lived singlet states can be created with much weaker RF fields than previously used.

Findings

Long-lived singlet states are achievable with RF power more than 100 times lower than prior methods.

A theoretical model accurately describes the dependence of singlet lifetime on RF power.

Long-lived coherence between singlet and triplet states can be preserved without RF spin-locking.

Abstract

We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that in many biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.