Superconducting Instabilities in Strongly Correlated Infinite-Layer Nickelates

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Superconductivity in infinite-layer nickelates represents a significant addition to unconventional superconductors.
• These materials exhibit strongly correlated multiorbital electronic properties crucial for understanding their superconducting behavior.

Purpose of the Study:

• To compute the leading superconducting instability in infinite-layer nickelates driven by magnetic fluctuations.
• To investigate the doping dependence of Ni orbitals (d_{x^{2}-y^{2}} and d_{z^{2}}) and self-doping bands.
• To uncover the pairing symmetry and its transition mechanism.

Main Methods:

• Computational analysis incorporating strongly correlated multiorbital electronic degrees of freedom.
• Inclusion of doping dependence for Ni d_{x^{2}-y^{2}} and d_{z^{2}} orbitals and the self-doping band.
• Analysis of magnetic fluctuations driving superconducting instability.

Main Results:

• A transition in superconducting pairing symmetry from d-wave to nodal s_{±} was identified.
• This transition is driven by strong fluctuations in the d_{z^{2}}-dominated orbital states.
• The study provides insights into the superconducting condensate properties.

Conclusions:

• The findings elucidate the mechanism behind superconductivity in infinite-layer nickelates.
• The predicted transition in pairing symmetry offers a new perspective on unconventional superconductivity.
• Results are discussed in the context of experimental observations of superconducting gap structure.