The lifetime Ts of a long‐lived nuclear spin state (LLS) could be much longer than the longitudinal order T₁. Many spin systems were used to produce long‐lived states, including two or more homonuclear spins that couple to each other. For multiple homonuclear spins with rather small chemical shift difference, normally it is difficult to selectively control the spins and then to prepare a LLS. Herein, we present a scheme that prepares different spin orders in a multi‐spin system by using optimal control and numerical calculation. By experimentally measuring the lifetime of the states, we find that for a three‐spin physical system, although there are many forms of state combinations with different spin orders, each component has its own lifetime.

中文翻译：

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使用最优控制方法在多旋转系统中制备长寿命状态。

长寿命核自旋态（LLS）的寿命Ts可能比纵向阶数T ₁长得多。许多自旋系统用于产生长寿命状态，包括两个或多个彼此耦合的同核自旋。对于具有相当小的化学位移差异的多个同核自旋，通常难以选择性地控制自旋然后制备LLS。本文中，我们提出了一种通过使用最佳控制和数值计算在多旋转系统中准备不同旋转顺序的方案。通过实验测量状态的生命周期，我们发现对于三自旋物理系统，尽管有许多形式的状态组合具有不同的自旋顺序，但每个组件都有其自己的生命周期。