Si Liang, Janson Oleg, Li Gang, Zhong Zhicheng, Liao Zhaoliang, Koster Gertjan, Held Karsten
Institut für Festkörperphysik, TU Wien, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria.
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
Phys Rev Lett. 2017 Jul 14;119(2):026402. doi: 10.1103/PhysRevLett.119.026402. Epub 2017 Jul 13.
SrRuO_{3} heterostructures grown in the (111) direction are a rare example of thin film ferromagnets. By means of density functional theory plus dynamical mean field theory we show that the half-metallic ferromagnetic state with an ordered magnetic moment of 2 μ_{B}/Ru survives the ultimate dimensional confinement down to a bilayer, even at elevated temperatures of 500 K. In the minority channel, the spin-orbit coupling opens a gap at the linear band crossing corresponding to 3/4 filling of the t_{2g} shell. We predict that the emergent phase is Haldane's quantum anomalous Hall state with Chern number C=1, without an external magnetic field or magnetic impurities.
沿（111）方向生长的SrRuO₃异质结构是薄膜铁磁体的罕见例子。通过密度泛函理论加动态平均场理论，我们表明，即使在500 K的高温下，具有2 μB/Ru有序磁矩的半金属铁磁态在降至双层的最终维度限制下仍能存在。在少数载流子通道中，自旋轨道耦合在对应于t₂g壳层3/4填充的线性带交叉处打开一个能隙。我们预测，在没有外部磁场或磁性杂质的情况下，出现的相是陈数C = 1的霍尔丹量子反常霍尔态。
