BaCuS$_{2}$: A Superconductor with Moderate Electron-Electron Correlation
Yuhao Gu1, Xianxin Wu1, Kun Jiang1, and Jiangping Hu1,2*
1Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China 2CAS Center of Excellence in Topological Quantum Computation and Kavli Institute of Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
Abstract：We show that the layered-structure BaCuS$_{2}$ 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 $d$–$p$ $\sigma^*$-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, BaCuS$_{2}$ 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.
收稿日期: 2020-09-16
出版日期: 2020-11-18
引用本文:
. [J]. 中国物理快报, 2021, 38(1): 17501-017501.
Yuhao Gu, Xianxin Wu, Kun Jiang, and Jiangping Hu. BaCuS$_{2}$: A Superconductor with Moderate Electron-Electron Correlation. Chin. Phys. Lett., 2021, 38(1): 17501-017501.
Ba$_{3}$Cu$_{2}$S$_{5}$ shares similar electronic physics with BaCuS$_{2}$, and Cu is also in square pyramidal coordination. Please find more details in our Supplementary Information.
2021, Vol. 38 
