论文标题
在Van-der-Waals Ferromagnet CR2SI2TE6上的外延BI2SE3超薄薄膜中狄拉克电子的调节
Modulation of Dirac electrons in epitaxial Bi2Se3 ultrathin films on van-der-Waals ferromagnet Cr2Si2Te6
论文作者
论文摘要
当拓扑绝缘子BI2SE3的超薄薄膜通过角度分辨光学光谱光谱法上生长，我们研究了狄拉克孔状态及其调节。我们观察到CST上6个五重杆层（QL）bi2se3中的无间隙狄拉克孔表面状态，而Dirac锥体在2QL对应物中的间隙为0.37 eV。有趣的是，这一差距比SI上的BI2SE3膜的差距要大得多（111）。我们还揭示了CST的铁磁过渡的间隙幅度没有明显的变化，这表明磁接近效应的特性长度和能量尺度很小。目前的结果表明，界面耦合在调节拓扑 - 绝缘体杂种中调节狄拉克电子的关键作用。
We investigated the Dirac-cone state and its modulation when an ultrathin film of topological insulator Bi2Se3 was epitaxially grown on a van-der-Waals ferromagnet Cr2Si2Te6 (CST) by angle-resolved photoemission spectroscopy. We observed a gapless Dirac-cone surface state in 6 quintuple-layer (QL) Bi2Se3 on CST, whereas the Dirac cone exhibits a gap of 0.37 eV in 2QL counterpart. Intriguingly, this gap is much larger than those for Bi2Se3 films on Si(111). We also revealed no discernible change in the gap magnitude across the ferromagnetic transition of CST, suggesting the very small characteristic length and energy scale of the magnetic proximity effect. The present results suggest a crucial role of interfacial coupling for modulating Dirac electrons in topological-insulator hybrids.
