Divilov Simon, Wan Wen, Dreher Paul, Bölen Emre, Sánchez-Portal Daniel, Ugeda Miguel M, Ynduráin Félix
Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
J Phys Condens Matter. 2021 Jun 9;33(29). doi: 10.1088/1361-648X/ac00da.
By means of spin-resolved density functional theory calculations using both atomic orbitals and plane-wave basis codes, we study the electronic and magnetic ground state of single-layer NbSe. We find that, for all the functionals considered, the most stable solution in this two-dimensional (2D) superconductor is the ferrimagnetic ground state with a magnetic moment of 1.09 at the Nb atoms and of 0.05 at the Se atoms pointing in the opposite direction. Our calculations show that the ferrimagnetic state precludes the development of charge density wave (CDW) order and their coexistence in the single-layer limit, unless graphene is considered as a substrate. The spin-resolved calculated density of states (DOS), a key fingerprint of the electronic and magnetic structure of a material, unambiguously reproduces the experimental DOS measured by scanning tunneling spectroscopy in single-layer NbSe. Our work sets magnetism into play in this prototypical correlated 2D material, which is crucial to understand the formation mechanisms of 2D superconductivity and CDW order.
通过使用原子轨道和平面波基组代码的自旋分辨密度泛函理论计算，我们研究了单层NbSe的电子和磁基态。我们发现，对于所有考虑的泛函，在这种二维（2D）超导体中最稳定的解是亚铁磁基态，其中Nb原子的磁矩为1.09，Se原子的磁矩为0.05，方向相反。我们的计算表明，亚铁磁态排除了电荷密度波（CDW）序的发展及其在单层极限下的共存，除非将石墨烯视为衬底。自旋分辨计算的态密度（DOS），是材料电子和磁结构的关键指纹，明确再现了通过扫描隧道光谱法在单层NbSe中测量的实验DOS。我们的工作在这种典型的关联二维材料中引入了磁性，这对于理解二维超导性和CDW序的形成机制至关重要。
