论文标题
相关氧化物异质结构中层间电荷转移的特征长度
Characteristic Lengths of Interlayer Charge-Transfer in Correlated Oxide Heterostructures
论文作者
论文摘要
使用层间相互作用来控制具有原子尺度设计的功能异质结构，已成为当今最有效的接口工程策略之一。在这里，我们演示了结晶LaFeo3缓冲层对无定形和结晶Laalo3/srtio3异质结构的影响。 LAFEO3缓冲层在LAALO3/SRTIO3系统中起到了能量偏爱的电子受体，从而导致界面载体密度的调节以及金属对绝缘体的过渡。对于无定形和结晶Laalo3/srtio3异质结构，当LaFeo3层厚度分别横穿3和6个单位细胞时，可以发现金属对隔离剂转变。通过氧化还原反应介导的和极性 - 曲折主导的电荷转移的不同特征长度来解释了这种不同的临界LaFeo3厚度，分别由界面原子接触和Thomas-Fermi筛选效果控制。我们的结果不仅阐明了跨氧化物异质结构的复杂层间电荷转移，而且还提供了一种新的途径，可以精确地在功能界面下定制电荷转移过程。
Using interlayer interaction to control functional heterostructures with atomic-scale designs has become one of the most effective interface-engineering strategies nowadays. Here, we demonstrate the effect of a crystalline LaFeO3 buffer layer on amorphous and crystalline LaAlO3/SrTiO3 heterostructures. The LaFeO3 buffer layer acts as an energetically favored electron acceptor in both LaAlO3/SrTiO3 systems, resulting in modulation of interfacial carrier density and hence metal-to-insulator transition. For amorphous and crystalline LaAlO3/SrTiO3 heterostructures, the metal-to-insulator transition is found when the LaFeO3 layer thickness crosses 3 and 6 unit cells, respectively. Such different critical LaFeO3 thicknesses are explained in terms of distinct characteristic lengths of the redox-reaction-mediated and polar-catastrophe-dominated charge transfer, controlled by the interfacial atomic contact and Thomas-Fermi screening effect, respectively. Our results not only shed light on the complex interlayer charge transfer across oxide heterostructures but also provides a new route to precisely tailor the charge-transfer process at a functional interface.
