Nickelate superconductors share a common electronic fingerprint

June 8, 2026 feature Nickelate superconductors share a common electronic fingerprint Ingrid Fadelli Author Sadie Harley Scientific Editor Robert Egan Associate Editor Superconductors, materials that conduct electricity with zero electrical resistance at specific temperature ranges, have proved very promising for the development of quantum computers and other cutting-edge technologies. While most of these materials become superconducting at very low temperatures, others exhibit superconductivity at higher temperatures. Two types of materials that are known to be high-temperature semiconductors are cuprates (i.e., compounds containing negatively charged copper ions) and nickelates (i.e., compounds that contain negatively charged nickel-oxygen ions). While cuprates have been known to be superconductors for decades, nickelates were only recently found to exhibit superconductivity at unusually high temperatures. Researchers at University of British Columbia (UBC), Argonne National Laboratory, and the Canadian Light Source (CLS), carried out a study aimed at better understanding how the electronic structure of nickelates contributes to their superconductivity. Their findings, published in Nature Physics, offer hints about the electronic underpinnings of superconductivity in nickelates at a microscopic scale, showing that these materials' electronic structure shares some similarities with that of cuprates. "In our recent study, we focused on an exciting new family of superconducting materials: layered nickelates," Andrea Damascelli, principal investigator at UBC's Quantum Matter Institute and senior author of the paper, told Phys.org. "Superconductors are materials that can conduct electricity with zero resistance, and discovering new superconductors is important both for fundamental science and for potential future technologies, including more efficient energy systems, advanced computing, and powerful magnets used in medical imaging." Layered nickelates, which are made up of two-dimensional NiO2 layers separated by rare-earth or lanthanide layers, have emerged as particularly interesting high-temperature superconductors. This is because their electronic structures and magnetic properties closely mirror those of cuprates. "Nickel-based oxides have long been viewed as promising candidates because of their structural and electronic similarities to cuprates, but only recently was superconductivity observed in layered nickelates under pressure," said Christine C. Au-Yeung, graduate student in Damascelli's group at UBC and lead author of this study. "Our paper came about from this combination of discovery and open questions. We wanted to identify which electronic states are most important, how they interact with one another, and what role the layered crystal structure plays in enabling superconductivity. We were also interested in understanding how similar these nickelates really are to copper-based superconductors, and whether they might reveal something fundamentally new." Probing the electronic structure of nickelates The primary goal of the team's study was to explore the electronic structure of layered nickelates in greater detail and at a microscopic scale. Their hope was to shed light on the underpinnings of unconventional superconductivity both in nickelates and other superconductors with similar magnetic and electronic characteristics. "We found that multilayer nickelates share a common electronic 'fingerprint,'" explained Au-Yeung. "This fingerprint is the Fermi surface, which can be thought of as the boundary between occupied and unoccupied electronic states in a material. Its shape is extremely important because it tells us how the conducting electrons move through the material, how they interact with one another, and how they may eventually form a superconducting state." As part of their study, the team studied different bulk crystals of multilayered nickelates. They specifically studied La₃Ni₂O₇, a material that can have different stacking arrangements and crystal structures. "A key part of the study was our ability to grow and isolate crystals with two different structural forms of this compound, each with a different stacking arrangement of atomic layers," said John Mitchell, senior scientist at Argonne National Lab. "Despite these structural differences, the most important electronic features remained essentially the same." Using this approach, the team was able to uncover a shared electronic phenomenology across multilayer nickelates. This common signature could help to better understand why superconductivity emerges in these materials. "To uncover this, we combined experimental measurements with theoretical calculations," said Au-Yeung. "Experimentally, we used angle-resolved photoemission spectroscopy, or ARPES, a technique that allows us to directly map how electrons move inside a material by measuring their energy and momentum, and reconstruct band dispersion and Fermi surfaces. "One way to think about it is as a powerful microscope for quantum matter: rather than taking a picture of atoms, it reveals the electronic states that govern the material's properties." Au-Yeung and her colleagues compared the ARPES measurements they collected at the Quantum Materials Spectroscopy Center beamline at CLS with the results of theoretical calculations predicting the electronic structure of different multi-layer nickelates. This allowed them to interpret the data they had collected and shed light on the possible electronic origins of the features they observed. Comparing the electronic structures of cuprates and nickelates The researchers were ultimately able to identify a magnetic order in multi-layer nickelates, known as a spin-density wave, and its fingerprint on the electronic structure. Essentially, this means that electron spins form an ordered pattern inside these materials. "The order we observed is strong and coherent enough to result in a Fermi surface reconstruction, meaning that it reorganizes the way electrons move and produces a clear signature in our ARPES measurements," explained Damascelli. "This result is important because it helps connect different experimental views of the same material. ARPES is a very powerful technique for measuring electronic structure, but it is primarily sensitive to the near-surface region, which may not always fully represent the bulk of the material. "By contrast, techniques such as X-ray and neutron scattering probe the bulk, but they do not directly reveal how electrons move through the material." The researchers showed that the electronic structure of nickelates observed with ARPES is closely related to ordering phenomena detected using bulk-sensitive probes. Their work thus offers a comprehensive view of both the magnetic and electronic properties of multilayer nickelates. "We also found strong similarities between the electronic states in multilayer nickelates and those in cuprates, the best-known high-temperature superconductors," said Damascelli. "In cuprates, superconductivity is widely associated with a d-wave pairing symmetry, specifically linked to electronic states with dx2-y2 orbital character and a strong involvement of oxygen orbitals. Remarkably, we found a very similar orbital character in the nickelates." The team's observations do not entail that nickelates and cuprates have identical electronic structures or that their superconductivity is the same. Nonetheless, they suggest that the physical mechanisms underpinning the emergence of superconductivity in these two families of materials are similar. "This comparison is especially valuable because it allows us to ask which features are universal to high-temperature superconductivity and which are specific to a particular material family," said Mitchell. "The broader implication of our work is that layered nickelates may provide a new platform for studying the mechanisms behind unconventional superconductivity." Implications for the study of unconventional superconductors The team's findings ultimately contribute to the understanding of unconventional superconductors. In the future, they could guide the search for new high-temperature superconductors with more advantageous properties, which could be used to develop quantum technologies, medical imaging devices, and other advanced systems. "Looking ahead, our goal is to understand the electronic properties of layered nickelates in even greater detail, especially how their superconducting and magnetic states are connected," said Damascelli. "One exciting direction will be to study these materials using time-resolved ARPES, a capability developed by our group (see our recent review by Fabio Boschini, Marta Zonno, and Andrea Damascelli)." "At the same time, we are learning more about how to tailor the structures of layered nickelates," added Mitchell, "offering us a variety of platforms for measurements such as these." In their next studies, the team plans to study nickelates, cuprates, and other unconventional superconductors using time-resolved ARPES, a technique that can capture the responses of electrons to light on extremely short timescales. This technique relies on ultrafast laser pulses to drive electrons out of equilibrium, allowing researchers to observe how they relax back into their original state. "This can reveal important information that is difficult to access in equilibrium measurements, such as how different electronic states interact with one another, and which interactions are most important for superconductivity," added Damascelli. "By applying this approach to layered nickelates, we hope to gain deeper insight into how superconductivity emerges, how it competes or coexists with magnetic order, and how the relevant electronic states are coupled. "More broadly, this work could help clarify whether the mechanisms at play in nickelates are truly related to those in cuprates and may guide future efforts to design new superconducting materials with improved properties." Written for you by our author Ingrid Fadelli, edited by Sadie Harley, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You'll get an ad-free account as a thank-you. Publication details Christine C. Au-Yeung et al, Oxygen-centred planar orbitals in the electronic structure and spin-density-wave reconstruction of multilayer nickelates, Nature Physics (2026). DOI: 10.1038/s41567-026-03286-4. Journal information: Nature Physics Key concepts Electronic structureMagnetismOptics & lasersStructural propertiesSuperconductivity2-dimensional systemsMagnetic systemsSuperconductorsElectron techniques© 2026 Science X Network