论文标题
由界面电子 - phonon耦合在Bapbo $ _3 $/babio $ _3 $ BiLayer驱动的2D超导剂
2D superconductidy driven by interfacial electron-phonon coupling at the BaPbO$_3$/BaBiO$_3$ bilayer
论文作者
论文摘要
最近在Bapbo $ _3 $（BPO）和Babio $ _3 $（BBO）的接口上发现了2D超导性，这激励我们通过第一原则计算，深入研究电子和结构属性以及它们之间的关系以及它们之间的关系。我们的结果表明，在BPO/BBO双层的BBO侧的最内向层保留了呼吸扭曲，电荷顺序和代表父级化合物BBO的半导体行为。另一方面，在界面上，呼吸畸变部分断裂，界面双离子与顶部BPO层之间的电荷转移。我们表明，两种类型的载体在界面共存，即来自pb离子的DELACALIGAT 3D SP状态，而BI的载体则来自PB离子和准2D状态。我们在2D BI状态之间获得了具有界面拉伸声子模式的2D BI状态之间的实质性电子耦合，并且可以解释临界温度实验观察到的关键温度的bellow 3.5 K.我们希望这些发现将激励未来的研究以探索以充电的半导体为BBO作为BBO作为BBO的不同接口，以触发这种诱人的2D dd dd。
The recent discovery of 2D superconductivity at the interface of BaPbO$_3$ (BPO) and BaBiO$_3$ (BBO) has motivated us to study in depth the electronic and structural properties and the relation between them in this particular heterostructure, by means of first-principles calculations. Our results indicate that the breathing distortions, the charge ordering and the semiconducting behaviour that characterize the parent compound BBO in its bulk form, are preserved at the innermost layers of the BBO side of the BPO/BBO bilayer. On the other hand, at the interface, there is a partial breaking of the breathing distortions with a concomitant charge transfer between the interfacial Bi ions and the on top BPO layer. We show that two types of carriers coexist at the interface, the delocalized 3D like sp states coming from Pb ions and the quasi 2D s states from the Bi ones. We obtain a substantial electron-phonon coupling between the 2D Bi states with the interfacial stretching phonon mode and a large density of states that can explain the critical temperature experimentally observed bellow 3.5 K. We hope these findings will motivate future research to explore different interfaces with charge ordered semiconductors as BBO in order to trigger this fascinating 2D behavior.
