Multiple quantum (MQ) NMR dynamics in an inhomogeneous spin chain, where the distances between the various pairs of neighboring spins can be different, has been studied in the approximation of nearest-neighbor dipole–dipole interaction (DDI). Though the fermion spectrum after performing the Jordan-Wigner transformation is not known, this article shows that the MQ NMR spectrum consists of MQ coherences of orders 0 and ±2 only, and their intensities are determined by the system’s fermion spectrum. As an example application of the theory developed, we calculate MQ NMR spectra of uniform, alternated and doubly alternated (with three different dipolar coupling constants) spin chains.

已经在最近邻偶极-偶极相互作用 (DDI) 的近似中研究了非均匀自旋链中的多量子 (MQ) NMR 动力学，其中各对相邻自旋之间的距离可能不同。尽管执行 Jordan-Wigner 变换后的费米子谱未知，但本文表明 MQ NMR 谱仅由 0 阶和 ±2 阶的 MQ 相干组成，其强度由系统的费米子谱决定。作为所开发理论的一个示例应用，我们计算了均匀、交替和双交替（具有三个不同的偶极耦合常数）自旋链的 MQ NMR 光谱。