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 (1H) nuclear magnetic resonance near earth's field.
@article{arxiv.2206.12025,
title = {Meridional composite pulses for low-field magnetic resonance},
author = {Sven Bodenstedt and Morgan W. Mitchell and Michael C. D. Tayler},
journal= {arXiv preprint arXiv:2206.12025},
year = {2022}
}