Ab initio quantum many-body description of superconducting trends in the cuprates
Zhi‐Hao Cui, Junjie Yang, Johannes Tölle, Hong‐Zhou Ye, Shunyue Yuan, Huanchen Zhai, Gunhee Park, Raehyun Kim, Xing Zhang, Lin Lin, Timothy C. Berkelbach, Garnet Kin‐Lic Chan
Abstract
Using a systematic ab initio quantum many-body approach that goes beyond low-energy models, we directly compute the superconducting pairing order and estimate the pairing gap of several doped cuprate materials and structures within a purely electronic picture. We find that we can correctly capture two well-known trends: the pressure effect, where the pairing order and gap increase with intra-layer pressure, and the layer effect, where the pairing order and gap vary with the number of copper-oxygen layers. From these calculations, we observe that the strength of superexchange and the covalency at optimal doping are the best descriptors for these trends. Our microscopic analysis further identifies that strong short-range spin fluctuations and multi-orbital charge fluctuations drive the development of the pairing order. Our work illustrates the possibility of a material-specific ab initio understanding of unconventional high-temperature superconducting materials. The authors present a material-specific ab initio understanding of doped cuprates. Their method correctly captures two known experimental trends: the pressure effect, where the pairing order and gap increase with intra-layer pressure, and the layer effect, where the pairing order and gap vary with the number of copper-oxygen layers.