Meridional composite pulses for low-field magnetic resonance

TL;DR

This paper introduces meridional composite pulses that enable robust spin control in low-field magnetic resonance, demonstrating effective $z$ inversion despite environmental magnetic field variations.

Contribution

The paper presents a novel class of error-tolerant pulse sequences for low-field NMR, expanding control techniques beyond traditional high-field methods.

Findings

Achieved robust $z$ inversion in proton NMR near Earth's field.

Demonstrated band-pass excitation properties comparable to high-field pulses.

Developed pulse sequences tolerant to large-angle magnetic field reorientations.

Abstract

We discuss procedures for error-tolerant spin control in environments that permit transient, large-angle reorientation of magnetic bias field. Short sequences of pulsed, non-resonant magnetic field pulses in a laboratory-frame meridional plane are derived. These are shown to have band-pass excitation properties comparable to established amplitude-modulated, resonant pulses used in high, static-field magnetic resonance. Using these meridional pulses, we demonstrate robust $z$ inversion in proton ($^{1}$H) nuclear magnetic resonance near earth's field.