NMR Time Reversal as a Probe of Incipient Turbulent Spin Dynamics

TL;DR

This paper demonstrates the use of NMR time reversal techniques to investigate and control turbulent spin dynamics in highly magnetized liquid helium mixtures, significantly extending spin precession stability.

Contribution

It introduces a novel application of magic sandwich NMR pulse sequences for probing and stabilizing turbulent nuclear spin behaviors in superfluid helium mixtures.

Findings

Successful inversion of dipolar interactions using magic sandwich sequences.

Extended precession lifetimes by over three orders of magnitude.

Ability to stabilize otherwise unstable nuclear precession modes.

Abstract

We demonstrate time reversal of nuclear spin dynamics in highly magnetized dilute liquid 3He-4He mixtures through effective inversion of long-range dipolar interactions. These experiments, which involve using magic sandwich NMR pulse sequences to generate spin echoes, probe the spatiotemporal development of turbulent spin dynamics and promise to serve as a versatile tool for the study and control of dynamic magnetization instabilities. We also show that a repeated magic sandwich pulse sequence can be used to dynamically stabilize modes of nuclear precession that are otherwise intrinsically unstable. To date, we have extended the effective precession lifetimes of our magnetized samples by more than three orders of magnitude.