We show that the layered-structure BaCuS₂ is a moderately correlated electron system in which the electronic structure of the CuS layer bears a resemblance to those in both cuprates and iron-based superconductors. Theoretical calculations reveal that the in-plane d–p σ ^*-bonding bands are isolated near the Fermi level. As the energy separation between the d and p orbitals are much smaller than those in cuprates and iron-based superconductors, BaCuS₂ is expected to be moderately correlated. We suggest that this material is an ideal system to study the competitive/collaborative nature between two distinct superconducting pairing mechanisms, namely the conventional BCS electron-phonon interaction and the electron-electron correlation, which may be helpful to establish the elusive mechanism of unconventional high-temperature superconductivity.

我们表明，层状结构 BaCuS ₂是一个中等相关的电子系统，其中 CuS 层的电子结构与铜酸盐和铁基超导体中的电子结构相似。理论计算表明，平面内d – p σ ^* -键带在费米能级附近是孤立的。由于d和p轨道之间的能量分离远小于铜酸盐和铁基超导体中的能量分离，BaCuS ₂预计中度相关。我们认为这种材料是研究两种不同超导配对机制之间的竞争/协作性质的理想系统，即常规的 BCS 电子-声子相互作用和电子-电子相关性，这可能有助于建立非常规高的难以捉摸的机制。 -温度超导性。