In a groundbreaking advancement in the field of superconductivity, a research team led by Professor Denver Li Danfeng at the City University of Hong Kong (CityUHK) has unveiled an extraordinary magnetic-field-induced re-entrant superconductivity in infinite-layer nickelates. This remarkable phenomenon defies longstanding scientific conventions by demonstrating that superconductivity, initially suppressed under magnetic fields, can surprisingly be revived at higher field intensities—a discovery that challenges the traditional view of the irreconcilable nature of magnetism and superconductivity.
Superconductivity, characterized by zero electrical resistance and the expulsion of magnetic fields (the Meissner effect), typically succumbs to external magnetic influences. Conventional wisdom holds that increasing magnetic field strength weakens and ultimately extinguishes the superconducting state by disrupting the electron pairs (Cooper pairs) responsible for this phase. However, the CityUHK-led team’s research, recently published in the esteemed journal Nature, reveals a dramatic anomaly in Eu-doped infinite-layer nickelates, where superconductivity exhibits a non-monotonic response to magnetic fields, showcasing a re-entrant behavior—transitioning from superconducting to normal and back to superconducting as the applied field intensifies.
This discovery was facilitated by the meticulous doping of infinite-layer nickelates with europium (Eu), a rare-earth element known to influence magnetic interactions. By finely tuning Eu incorporation, the team achieved an unprecedented experimental platform to scrutinize the interplay between electron pairing mechanisms and external magnetic perturbations. The experimental outcomes depict a complex landscape wherein superconductivity is first suppressed as magnetic field strength approaches roughly 15 tesla, only to remarkably re-emerge and sustain stability beyond this threshold, enduring even under magnet fields vastly exceeding 15 tesla.
Significantly, the re-entrant superconducting state revealed in this nickelate system exhibits a robustness hitherto unseen. Prior observations of re-entrant superconductivity in other material systems, such as heavy-fermion compounds, have demonstrated extreme sensitivity to the orientation of the applied magnetic field, constrained within a narrow angular margin of approximately 2° to 10°. Contrastingly, the nickelate superconductor maintains this re-entrant superconductivity across an expansive angular spectrum—from parallel to perpendicular magnetic field alignments—indicating an inherent isotropic resilience that compels a reevaluation of the microscopic mechanisms at play.
The classical field compensation mechanism, often invoked to explain such re-entrant phenomena, assumes that magnetic interactions counterbalance the pair-breaking effects to restore superconductivity. Nevertheless, the unprecedented wide angular stability and persistence at high fields suggest that this simplistic model is insufficient. Instead, magnetic interactions may serve not merely as antagonistic forces but as facilitators enhancing electron pairing, potentially stabilizing unconventional superconducting states where magnetism and superconductivity coalesce synergistically.
Infinite-layer nickelates have captivated condensed matter physicists since their superconducting properties were first observed in 2019. Their electronic structure bears notable resemblance to the celebrated cuprate high-temperature superconductors, propelling them into the spotlight as promising materials for probing unconventional superconductivity. Professor Li, serving as both a pioneer and lead in earlier seminal studies at Stanford University, spearheads this contemporary investigation, pushing the boundaries of our understanding by uncovering re-entrant superconductivity in these materials.
From a theoretical perspective, this reported phenomenon bridges superconductivity with magnetism-driven quantum phases, a nexus that has intrigued and eluded researchers for decades. The manifestation of field-enhanced superconductivity draws compelling parallels to heavy-fermion superconductors, where intricate electron correlations under intense magnetic environments yield exotic quantum states. This new evidence in oxide superconductors invigorates theories postulating intertwined order parameters and highlights the need to revisit fundamental assumptions regarding electron pairing symmetries and the role of magnetic fluctuations.
Potential applications of this discovery are profound. Superconductors capable of sustaining zero resistance under intense and variable magnetic fields widen the scope for practical deployment in magnet technology, quantum computing elements, and power transmission systems. The robustness across wide angular ranges particularly alleviates engineering challenges related to device orientation and stability in fluctuating electromagnetic environments.
In reflecting on this seminal breakthrough, Professor Li emphasized the paradigm-shifting implications: “Our discovery unveils a novel field-induced superconducting phase in infinite-layer nickelates that parallels discoveries in heavy-fermion systems. It not only deepens our grasp of high-temperature superconductivity but also unfolds an unprecedented landscape where magnetism catalyzes electron pairing rather than suppressing it. This insight paves the way for designing unconventional superconductors tailored through magnetic interactions.”
This research exemplifies the power of international collaboration, involving partnerships with Southern University of Science and Technology, the Guangdong-Hong Kong-Macao Greater Bay Area Quantum Science Center, the High Magnetic Field Science Center of the Hefei Institutes of Physical Science at the Chinese Academy of Sciences, the National Pulsed High Magnetic Field Science Center at Huazhong University of Science and Technology, Tsinghua University, among others. Financial backing from prominent funding agencies including the National Natural Science Foundation of China, National Key R&D Programme, the Research Grants Council of Hong Kong, and the U.S. Department of Energy underpinned this formidable scientific endeavor.
Professor Li’s insights combined with this discovery mark a pivotal moment in superconductivity research. The ability to “revive” superconductivity through magnetic fields not only enriches the scientific narrative about the coexistence and competition between magnetism and superconductivity but also inspires the pursuit of next-generation materials where tailored magnetic environments engineer bespoke electronic phases. These advancements herald a future where the confluence of high-field physics and correlated electron systems unlocks transformative technologies.
Subject of Research: Not applicable
Article Title: CityUHK physicist leads study revealing that magnetic fields can “revive” superconductivity in nickelates
News Publication Date: 23-Apr-2026
Web References:
https://www.nature.com/articles/s41586-026-10547-y
http://dx.doi.org/10.1038/s41586-026-10547-y
Image Credits: City University of Hong Kong
Keywords
Superconductivity, Re-entrant Superconductivity, Infinite-layer Nickelates, Magnetic Fields, Europium Doping, High Magnetic Field Stability, Electron Pairing, Oxide Superconductors, Magnetism and Superconductivity Coexistence, Quantum Phenomena, High-Temperature Superconductivity, Condensed Matter Physics
Tags: City University of Hong Kong physics researchCooper pair disruption by magnetic fieldsEu doping in superconducting materialseuropium-doped nickelatesinfinite-layer nickelates superconductivityinterplay between magnetism and superconductivitymagnetic field effects on superconductorsmagnetic-field-induced re-entrant superconductivityMeissner effect in nickelatesnon-monotonic superconductivity behaviorreactivation of superconductivity under magnetic fieldszero resistance superconducting states
