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.
@article{arxiv.2206.14771,
title = {The role of electron polarization on nuclear spin diffusion},
author = {Alessandro Chessari and Samuel F. Cousin and Sami Jannin and Quentin Stern},
journal= {arXiv preprint arXiv:2206.14771},
year = {2023}
}