论文标题
超导状态对分层材料中杂质位置的敏感性
Sensitivity of superconducting states to the impurity location in layered materials
论文作者
论文摘要
源自掺杂的拓扑绝缘体BI $ _2 $ se $ _3 $的多层超导体家族，对非磁性疾病异常强大。最近的实验研究强调了一个事实，即杂质的位置可能对这种令人困惑的鲁棒性发挥关键作用。在这里，我们研究了四种不同类型的杂质的影响，即现场，间隙，插入和极性对超导临界温度的影响。我们发现，散射电位的不同组件取决于杂质构型和轨道的选择，用于对正常状态的有效低能量描述。对于BI $ _2 $ SE SE $ _3 $的超导体的特定情况，我们发现只有杂质配置的对称份额有助于散射，因此极性杂质完全不活跃。我们还发现，与现场或间质杂质的情况相反，在正常状态的哈密顿量中，更有主导的质量不足项可以使超导状态更加强大。
The family of multi-layered superconductors derived from the doped topological insulator Bi$_2$Se$_3$ has been found to be unusually robust against non-magnetic disorder. Recent experimental studies have highlighted the fact that the location of impurities could play a critical role for this puzzling robustness. Here we investigate the effects of four different types of impurities, on-site, interstitial, intercalated and polar, on the superconducting critical temperature. We find that different components of the scattering potential are active depending on the impurity configuration and choice of orbitals for the effective low-energy description of the normal state. For the specific case of Bi$_2$Se$_3$-based superconductors, we find that only the symmetric share of impurity configurations contribute to scattering, such that polar impurities are completely inactive. We also find that a more dominant mass-imbalance term in the normal-state Hamiltonian can make the superconducting state more robust to intercalated impurities, in contrast to the case of on-site or interstitial impurities.
