论文标题
电子极化在核自旋扩散中的作用
The role of electron polarization on nuclear spin diffusion
论文作者
论文摘要
动态核极化（DNP）能够通过产生过平衡的核自旋极化来通过数量级来增强核磁共振中的信号。核自旋极化在顺磁掺杂剂附近的扩散是DNP的关键步骤，但仍未得到充分了解。在这封信中，我们表明电子自旋的极化控制在1.2 K和7 t下DNP样品中质子自旋扩散的速率。在越来越高的电子极化下，自旋扩散消失。我们使用2个核-1个电子模型和Lindblad的主方程合理化了结果，该方程在文献中概括了先前存在的模型，并在质量上说明了实验性观察到的自旋扩散动力学。
Dynamic nuclear polarization (DNP) is capable of boosting signals in nuclear magnetic resonance by orders of magnitude by creating out-of-equilibrium nuclear spin polarization. The diffusion of nuclear spin polarization in the vicinity of paramagnetic dopants is a crucial step for DNP and remains yet not well understood. In this Letter, we show that the polarization of the electron spin controls the rate of proton spin diffusion in a DNP sample at 1.2 K and 7 T; at increasingly high electron polarization, spin diffusion vanishes. We rationalize our results using a 2 nucleus - 1 electron model and Lindblad s Master equation, which generalizes preexisting models in the literature and qualitatively accounts for the experimental observed spin diffusion dynamics.
