K掺杂SrAsO₃中类BaBiO₃超导钙钛矿的预测
Prediction of BaBiO$_3$-like superconducting perovskites in K-doped SrAsO$_3$
AI总结：
研究人员通过第一性原理计算，预测K掺杂SrAsO₃可得到类BaBiO₃超导钙钛矿，当K掺杂量超60%时体系动力学稳定，HSE06泛函修正下Sr₀.₄K₀.₆AsO₃的Tc可达44.3 K。
AI中文摘要：
采用第一性原理计算，我们预测了一种新型钙钛矿化合物SrAsO₃。未掺杂的立方相具有显著的软声子不稳定性，在Sr位掺杂K后，这种不稳定性会逐渐被抑制。当K掺杂水平高于约60%时，立方相变为动力学稳定相，且稳定后的K掺杂相为金属态，具有预测的常规声子介导超导性。此外，包含非局域交换相互作用会拓宽电子带宽、增强电声耦合（EPC）强度，并提高这些掺杂化合物的超导转变温度（Tc）。特别地，经HSE06杂化交换关联泛函修正的EPC常数λ在Sr₀.₄K₀.₆AsO₃中达到1.41，对应预测的Tc为44.3 K。这些结果表明，SrAsO₃是一种由强电声耦合驱动的类BaBiO₃超导钙钛矿。
英文摘要：
Using first-principles calculations, we predict a new perovskite compound SrAsO$_3$ . The undoped cubic phase has pronounced soft-phonon instabilities, which are gradually suppressed upon K doping the Sr site. The cubic phase becomes dynamically stable for K-doping levels above approximately 60%, and the stabilized K-doped phases are metallic with predicted conventional phonon mediated superconductivity. Moreover, the inclusion of nonlocal exchange interactions broadens the electronic bandwidth, enhances the electron-phonon coupling (EPC) strength, and increases the superconducting transition temperature ($T_c$) of these doped compounds. In particular, the HSE06 hybrid exchange-correlation functional corrected EPC constant $λ$ reaches 1.41 for Sr$_{0.4}$K$_{0.6}$AsO$_3$, corresponding to a predicted $T_c$ of 44.3 K. These results suggest that SrAsO$_3$ is a BaBiO$_3$-like superconducting perovskite driven by strong electron-phonon coupling.
