论文标题
磁场引起的安德森本地化在轨道选择性抗Fiferromagnet bamn $ _2 $ bi $ _2 $
Magnetic-field-induced Anderson localization in orbital selective antiferromagnet BaMn$_2$Bi$_2$
论文作者
论文摘要
我们报告了在半填充的多梁抗铁磁铁（AF）BAMN $ _2 $ _2 $ bi $ _2 $中的金属 - 绝缘体过渡（MIT），该磁场垂直于AF Sublattices。我们通过扩展分析来发现MIT是由Anderson定位驱动的，而不是通常在密切相关的系统中预期的Anderson-Mott机制。电气和热电传输测量与电子带计算结合使用揭示了轨道依赖性的相关效应，在这些相关效果上，较弱和强烈相关的$ 3D $衍生的频带与电荷激发共存。 $ d_ {xy} $中的弱相关的Holelike载体 - 派生的频带主导了传输属性并展示了Anderson本地化，而其他$ 3D $频段则显示清晰的Mott样行为，其旋转下令订购为AF Sublattices。垂直磁场所起的调谐作用支持巡回式载体和AF波动之间的强旋转旋转耦合，这与它们的弱电荷耦合形成了鲜明的对比。
We report a metal-insulator transition (MIT) in the half-filled multiorbital antiferromagnet (AF) BaMn$_2$Bi$_2$ that is tunable by a magnetic field perpendicular to the AF sublattices. Instead of an Anderson-Mott mechanism usually expected in strongly correlated systems, we find by scaling analyses that the MIT is driven by an Anderson localization. Electrical and thermoelectrical transport measurements in combination with electronic band calculations reveal a strong orbital-dependent correlation effect, where both weakly and strongly correlated $3d$-derived bands coexist with decoupled charge excitations. Weakly correlated holelike carriers in the $d_{xy}$-derived band dominate the transport properties and exhibit the Anderson localization, whereas other $3d$ bands show clear Mott-like behaviors with their spins ordered into AF sublattices. The tuning role played by the perpendicular magnetic field supports a strong spin-spin coupling between itinerant holelike carriers and the AF fluctuations, which is in sharp contrast to their weak charge coupling.
