Superconductivity and antiferromagnetism in NdNiO2 and CaCuO2: A cluster DMFT study

We perform a comparative 2 x 2 real space cluster DMFT study on minimal models for NdNiO2 and CaCuO2 obtained from downfolding DFT states, using a Nambu formalism that allows for both superconducting and antiferromagnetic order. We produce a phase diagram in temperature and doping. We find that for the nickelate, like the cuprate, the stoichiometric compound is antiferromagnetic. We find superconductivity in a doping range bounded, with a small coexistence region, by the onset of antiferromagnetism at low doping and with transition temperature becoming immeasurably small at high doping. Superconductivity emerges at around the same hole doping for both compounds, but requires a larger deviation from half-filling for the nickelate. Both antiferromagnetic and superconducting order lead to a partial gapping of the d(x2-y2) Fermi surface sheet. Our similar results for the cuprate and nickelate suggest that nickelate superconductivity is cupratelike. We compare our results to the experimental phase diagram.

Automated summary

The study compares the properties of nickelate and cuprate compounds, finding that they exhibit antiferromagnetic and superconducting behavior, respectively, under stoichiometric conditions. The results also suggest that nickelate superconductivity is similar to cuprate superconductivity but requires a higher level of doping.