Development and Validation of Zero-field NMR Spectrometer Based on Compact Atomic Magnetometer

Abstract

Conventional high-field nuclear magnetic resonance (NMR) spectrometer necessitates advanced superconducting technology, which usually involves a magnet of large volume and high maintenance cost. Moreover, strong magnet often has severe magnetic field inhomogeneity, leading to NMR line broadening. Zero- to ultralow-field (ZULF) NMR emerged as a complementary approach to traditional high-field NMR techniques. In this paper, a portable zero-field NMR spectrometer based on a compact atomic magnetometer was developed, which adopted an integrated control system based on a multi-function data acquisition card (National Instruments PCIe-6353). The spectrometer is of a main magnetic field strength less than 1 nT and enables achieving high-resolution J-spectrum under zero-field environment. Specifically, a series of single pulse excitation experiments for the initial adiabatic state was carried out to calibrate the triaxial magnetic field coils. Then a modified composite pulse sequence was developed to further validate the performance of zero-field NMR spectrometer by single-spin control experiments for the 13C-1H spin system.

Keywords

• zero-field nmr
• j-spectroscopy
• atomic magnetometer
• single-spin control