Hernández-Tecorralco J, Meza-Montes L, Cifuentes-Quintal M E, de Coss R
Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48, 72570, Puebla, Puebla, México.
J Phys Condens Matter. 2020 Jun 10;32(25):255801. doi: 10.1088/1361-648X/ab78c0.
The effects of biaxial strain on the impurity-induced magnetism in P-doped graphene (P-graphene) and N-doped silicene (N-silicene) are studied by means of spin-polarized density functional calculations, using the supercell approach. The calculations were performed for three different supercell sizes 4 × 4, 5 × 5, and 6 × 6, in order to simulate three different dopant concentrations 3.1, 2.0 and 1.4%, respectively. For both systems, the calculated magnetic moment is 1.0 μ per impurity atom for the three studied concentrations. From the analysis of the electronic structure and the total energy as a function of the magnetization, we show that a Stoner-type model describing the electronic instability of the narrow impurity band accounts for the origin of sp-magnetism in P-graphene and N-silicene. Under biaxial strain the impurity band dispersion increases and the magnetic moment gradually decreases, with the consequent collapse of the magnetization at moderate strain values. Thus, we found that biaxial strain induces a magnetic quantum phase transition in P-graphene and N-silicene.
通过自旋极化密度泛函计算并采用超胞方法，研究了双轴应变对P掺杂石墨烯（P-石墨烯）和N掺杂硅烯（N-硅烯）中杂质诱导磁性的影响。针对三种不同的超胞尺寸4×4、5×5和6×6进行了计算，以便分别模拟三种不同的掺杂浓度3.1%、2.0%和1.4%。对于这两个体系，在三种研究浓度下，计算得到的每个杂质原子的磁矩均为1.0 μ。通过对电子结构以及作为磁化强度函数的总能量进行分析，我们表明，描述窄杂质带电子不稳定性的斯托纳型模型解释了P-石墨烯和N-硅烯中sp磁性的起源。在双轴应变下，杂质带色散增加，磁矩逐渐减小，在中等应变值时磁化强度随之消失。因此，我们发现双轴应变在P-石墨烯和N-硅烯中诱导了磁量子相变。
