Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588-0299, USA.
Phys Rev Lett. 2011 Oct 14;107(16):166601. doi: 10.1103/PhysRevLett.107.166601. Epub 2011 Oct 11.
First-principles density functional calculations demonstrate that a spin-polarized two-dimensional conducting state can be realized at the interface between two nonmagnetic band insulators. The (001) surface of the diamagnetic insulator FeS(2) (pyrite) supports a localized surface state deriving from Fe d orbitals near the conduction band minimum. The deposition of a few unit cells of the polar perovskite oxide LaAlO(3) leads to electron transfer into these surface bands, thereby creating a conducting interface. The occupation of these narrow bands leads to an exchange splitting between the spin subbands, yielding a highly spin-polarized conducting state distinct from the rest of the nonmagnetic, insulating bulk. Such an interface presents intriguing possibilities for spintronics applications.
第一性原理密度泛函计算表明，在两个非磁性带绝缘体的界面上可以实现自旋极化二维导电态。反铁磁绝缘体 FeS₂（黄铁矿）的（001）表面支持源自导带最小值附近 Fe d 轨道的局域表面态。几单位晶胞厚度的极性钙钛矿氧化物 LaAlO₃的沉积导致电子转移到这些表面带中，从而形成导电界面。这些窄带的占据导致自旋子带之间的交换劈裂，产生与非磁性绝缘体其余部分明显不同的高度自旋极化导电态。这种界面为自旋电子学应用提供了有趣的可能性。
