论文标题
揭开Kramers单分子磁铁中自旋晶格松弛的贡献
Unravelling the contributions to spin-lattice relaxation in Kramers single-molecule magnets
论文作者
论文摘要
对自旋如何与晶格振动相互作用并放松达到平衡的研究为其化学环境以及电子结构和分子组成之间的关系提供了独特的见解。尽管它对几个学科的重要性，从磁共振到量子技术，但由于对正确的自旋松弛机制的挑战性实验确定，仍然缺乏对磁分子晶体中自旋动力学的说服解释。我们将自发旋转动力学应用于CO（II）和DY（III）离子的一系列十二个配位复合物，在$ \ sim $ 240 $ 240化合物中选择，这些化合物在很大程度上涵盖了有关单分子磁体的文献，并且很好地代表了不同的自旋松弛方案。模拟表明，已知化合物的Orbach自旋松弛率主要取决于离子的零场分裂，几乎没有分子振动的细节。相反，拉曼松弛也受到低能声子特征的显着影响。这些结果提供了对限制单分子磁铁中旋转寿命的因素的完整理解，并通过使透明地区分Orbach和Raman弛豫机制来重新审视实验研究。
The study of how spin interacts with lattice vibrations and relaxes to equilibrium provides unique insights on its chemical environment and the relation between electronic structure and molecular composition. Despite its importance for several disciplines, ranging from magnetic resonance to quantum technologies, a convincing interpretation of spin dynamics in crystals of magnetic molecules is still lacking due to the challenging experimental determination of the correct spin relaxation mechanism. We apply ab initio spin dynamics to a series of twelve coordination complexes of Co(II) and Dy(III) ions selected among $\sim$240 compounds that largely cover the literature on single-molecule magnets and well represent different regimes of spin relaxation. Simulations reveal that the Orbach spin relaxation rate of known compounds mostly depends on the ions' zero-field splitting and little on the details of molecular vibrations. Raman relaxation is instead found to be also significantly affected by the features of low-energy phonons. These results provide a complete understanding of the factors limiting spin lifetime in single-molecule magnets and revisit years of experimental investigations by making it possible to transparently distinguish Orbach and Raman relaxation mechanisms.
