标题： 掺杂磁性杂质的拓扑狄拉克半金属：Mn掺杂的Cd$_3$As$_2$的电子结构 显示英文标题

标题： Doping Topological Dirac Semimetal with magnetic impurities: electronic structure of Mn-doped Cd$_3$As$_2$

摘要： 将狄拉克拓扑半金属（TSM）转变为外尔TSM相的前景，对于TSM的应用至关重要。磁性杂质的极化$d$能级产生的磁场具有尖锐的局部结构。磁性杂质在多大程度上以与施加的磁场相同的方式起作用，以及这种磁场对狄拉克TSM电子结构的影响是什么，是本文的研究主题。我们展示了在稀释合金范围内用Mn杂质进行替代掺杂的块体Cd$_3$As$_2$的电子结构计算。使用准粒子$GW$（QS$GW$）从头算电子结构计算，并结合$k \cdot p$模型哈密顿量计算。如预期的那样，我们在用Mn掺杂后观察到狄拉克点分裂成外尔点对。 我们还表明，掺锰的Cd$_3$As$_2$的电子结构可以通过在适当外部磁场下纯Cd$_3$As$_2$的电子结构来模拟。 对于不同磁场方向的块体Cd$_3$As$_2$的电导率的一些特性也进行了研究。 我们的结果为基于常规磁性外尔拓扑半金属中未发现的能带结构调制的独特器件功能提供了未来的机遇。 显示英文摘要

摘要： The prospect of transforming a Dirac topological semimetal (TSM) into a Weyl TSM phase, following doping by magnetic impurities, is central to TSM applications. The magnetic field from polarized $d$ levels of magnetic impurities produces a field with a sharp local structure. To what extent magnetic impurities act in the same manner as an applied field and what are the effects of such a field on the electronic structure of a Dirac TSM is the subject of this paper. We present electronic structure calculations of bulk Cd$_3$As$_2$ with substitutional doping of Mn impurities in the dilute alloy range. Quasi-particle $GW$ (QS$GW$) ab-initio electronic structure calculations are used in conjunction with $k \cdot p$ model Hamiltonian calculations. As expected, we observe the splitting of the Dirac points into pairs of Weyl points following the doping with Mn. We also show that the electronic structure of Mn-doped Cd$_3$As$_2$ can be emulated by the electronic structure of pristine Cd$_3$As$_2$ with an appropriate external magnetic field. Some properties of the conductivity of bulk Cd$_3$As$_2$ for different magnetic field orientations are also investigated. Our results inform future opportunities for unique device functionality based on band structure tuning not found in conventional magnetic Weyl TSM.