LaAlO₃/SrMnO₃(111)超晶格中的界面电荷重构

Interface Electronic Reconstruction in LaAlO₃/SrMnO₃(111) Superlattices

摘要: 利用第一性原理计算，在LaAlO₃/SrMnO₃(111)超晶格中实现了由极化电场驱动的电荷转移和半金属性。在(LaO₃)/Mn界面处，电子从LaAlO₃侧转移到SrMnO3₃中，占据Mn的eg轨道，从而形成该类超晶格中的半金属铁磁性。而在(SrO₃)/La界面处，极化电场使得空穴基本上是均匀分布于SrO₃面和LaO₃面的氧离子上，于是造成SrMnO₃中的G类反铁磁序。不过由于空穴的掺入，此类超晶格是金属性的。

Abstract: Based on extensive first-principle density functional calculations, we have revealed the charge transfer and half-metallic ferromagnetism induced by the polar electronic field in LaAlO₃/SrMnO₃ (111) superlattices. At the (LaO₃)/Mn interface, electrons transfer from LaAlO3₃ side to SrMnO₃ component and occupy eg orbital of Mn ions, inducing half-metallic ferromagnetism of this kind of superlattice. On the other hand, for the superlattices with (SrO₃)/La interface, the holes reside almost uniformly at the oxygen atoms of SrO₃ and LaO₃ atomic planes. With absence of the eg states at the Mn sites, bulk-like G-type AFM ordering were obvious. But this type superlattices are metallic because of hole transfer.