A collaboration led by Lauro Barreto Braz, a Ph.D. candidate at the Department of Materials Physics and Mechanics (FMT), and Luis Gregorio Godoy de Vasconcellos Dias da Silva, a professor in the same department, has made remarkable advances in the field of superconductivity. The article titled “Interlayer interactions in La₃Ni₂O₇ under pressure: From s^± to dₓᵧ-wave superconductivity”, published in the prestigious journal Physical Review Research (Phys. Rev. Research 7, 033023), explores the interlayer interactions in the bilayer nickelate La₃Ni₂O₇ under high pressure and how these interactions influence changes in superconducting pairing symmetries.

The Study

The research delves into the role of interlayer interactions in the superconducting behavior of La₃Ni₂O₇. Using a two-layer, two-orbital electronic model and Coulomb interaction terms (alongside approaches involving a random phase approximation matrix), the researchers analyzed how these interactions promote different symmetries in the superconducting gap.

The results indicate that interlayer interactions favor a dₓᵧ-wave superconducting pairing symmetry over the usual s^±-wave symmetry observed in their absence. These findings also reveal how these interactions enhance interorbital pairing and involve contributions from all electron pockets, leading to unique features in the gap function.

Significance of the Discovery

• Contributions to superconducting physics: Advances in the theoretical understanding of superconducting materials.
• Relevance of high-pressure materials: Paves the way for future discoveries of high-temperature superconductors.
• Impact on technological development: Applications include efficient electrical transmission and magnetic levitation devices.

About the Authors

This article reflects the collaborative work of researchers pushing the boundaries of material science. Lauro B. Braz and his advisor Luis G. G. V. Dias da Silva collaborated with George B. Martins, experts with extensive backgrounds in solid-state physics and complex electronic systems.

Publication

The article was published in the July 7, 2025, edition of Physical Review Research.

DOI: https://doi.org/10.1103/f4wf-56fl

Original Title: Interlayer interactions in La₃Ni₂O₇ under pressure: From s± to dₓᵧ-wave superconductivity

To learn more, check out the full article by clicking the link above!