GaAs掺Mn材料的局域电子结构和磁性

Local Electronic Structure and Magnetic Properties of(Ga,Mn)As

运用原子团模型研究了稀磁半导体G aA s掺M n的局域电子结构和磁性,计算采用基于密度泛函理论的离散变分方法.计算结果表明M n原子磁矩随掺杂浓度没有明显的变化,磁矩的数值与实验符合的较好.在包含两个M n原子的体系中M n原子之间是铁磁性偶合,表明体系具有铁磁性基态,每个M n原子的磁矩与掺杂一个M n原子时相近.对于不同的掺杂浓度,M n原子与最近邻A s原子之间均为反铁磁偶合,M n原子的3d电子与A s原子的4p电子之间有很强的杂化.

The local electronic structure and magnetic properties of diluted magnetic semiconductor （Ga,Mn）As has been studied by using Discrete Variational approach based on density functional theory. The magnetic moments per Mn atom change lightly with Mn concentration variation, and the value of magnetic moment is in good agreement with experiment. The coupling between Mn atoms in （Ga,Mn）As is found to be ferromagnetic, which indicates that our system has ferromagnetic grand state. For all doping concentrations, the coupling between Mn and the nearest neighbor As is found to be antiferromagnetic, and Mn 3d states hybridize strongly with As 4p states.