Electronic structure and magnetism of samarium and neodymium adatoms on free-standing graphene
Electronic structure and magnetism of samarium and neodymium adatoms on free-standing graphene
复制标题
DOI：
10.1103/physrevb.94.125113
复制
发表时间：
2016-09
影响因子：
3.7
通讯作者：
A. L. Kozub;A. Shick;F. Máca;J. Kolorenč;A. Lichtenstein
中科院分区：
文献类型：
--
作者：
A. L. Kozub;A. Shick;F. Máca;J. Kolorenč;A. Lichtenstein
采用超越传统密度泛函理论（DFT+U， DFT+HIA和DFT+ED）的方法研究了稀土原子吸附在独立石墨烯上的电子结构。研究了电子相关和自旋轨道耦合对磁性能的影响。DFT+U方法预测两个原子都携带局域磁矩（自旋和轨道），这与气相中Sm的非磁性基态构型相反。应用DFT${}+{}$ hubard - i （HIA）和DFT${}+{}$精确对角化（ED）方法解决了这一问题，得到了Sm原子具有6个$f$电子和$J=0$的非磁性基态。我们的计算表明，Nd原子仍然具有磁性，具有四个局部化的$f$电子，$J=4.0$。这些结论可以通过STM和XAS实验得到验证。
The electronic structure of selected rare-earth atoms adsorbed on a free-standing graphene was investigated using methods beyond the conventional density functional theory (DFT+U, DFT+HIA and DFT+ED). The influence of the electron correlations and the spin-orbit coupling on the magnetic properties has been examined. The DFT+U method predicts both atoms to carry local magnetic moments (spin and orbital) contrary to a nonmagnetic $f^6$ ($J=0$) ground-state configuration of Sm in the gas phase. Application of DFT${}+{}$Hubbard-I (HIA) and DFT${}+{}$exact diagonalization (ED) methods cures this problem, and yields a nonmagnetic ground state with six $f$ electrons and $J=0$ for the Sm adatom. Our calculations show that Nd adatom remains magnetic, with four localized $f$ electrons and $J=4.0$. These conclusions could be verified by STM and XAS experiments.