报告题目：Infinite-Layer Oxides and the Quest for High-temperature Superconductivity
报 告 人：Ariando，National University of Singapore (NUS)
报告时间：2026年6月2日10：30
报告地点：物理楼W105会议室
内容摘要：The discovery of superconductivity in the La-Ba-Cu-O cuprates by Bednorz and Müller launched the search for high-Tc superconductivity in complex oxides. Yet the structural complexity of cuprates has long made it difficult to isolate the essential ingredients for unconventional pairing. Infinite-layer oxides provide the simplest structure for addressing this question, consisting only of transition-metal–oxygen square planes separated by spacer ions. Remarkably, however, hole-doped superconductivity in this simplest limit remained unrealized for nearly four decades. At the same time, the emergence of infinite-layer nickelates has opened a new opportunity to test whether superconductivity beyond copper follows the same underlying principles. So far, however, superconductivity in infinite-layer nickelates has appeared only at much lower temperatures than in their cuprate counterparts.
In this talk, I will present our recent progress on both fronts. First, we realized a new superconducting infinite-layer nickelate, Sm-Eu-Ca-Ni-O (SECNO), with Tc approaching 40 K. Intriguingly, SECNO exhibits high-field-reentrant superconductivity as well as a hysteretic, field-history-dependent superconducting state. Magnetotransport, polarized neutron reflectometry, and anomalous Hall measurements further reveal an intrinsic ferromagnetic ground state coexisting with superconductivity. A Ginzburg-Landau model captures the splitting of the upper critical field, pointing to magnetism as a tunable internal control of superconductivity in correlated oxides. Second, I will present the realization of superconductivity in hole-doped infinite-layer cuprate thin films. In chemically doped Sr-Cu-O single-crystal thin films, transport and field-dependent measurements reveal superconducting transitions with onset temperatures up to 100 K. Hole doping is enabled by the combined effects of cation substitution and apical oxygen control. The realization of hole-doped infinite-layer cuprates with an onset temperature around 100 K opens new possibilities for further enhancing superconducting Tc . In particular, cationic-radius tuning may provide viable routes to elevating Tc reminiscent of recent advances in SECNO nickelate superconductors. Finally, as the isostructural analog of recently-discovered superconducting infinite-layer nickelates, hole-doped infinite-layer cuprates are pivotal in bridging the physics of cuprate and nickelate superconductors, offering a promising pathway toward a unified understanding of high-temperature superconductivity. For example, understanding electron-hole symmetry in infinite-layer cuprates may shed light on the so-far absent electron-doped superconductivity in nickelates.
报告人简介：
Ariando is a National Research Foundation (NRF) Investigator, National University of Singapore (NUS) Provost’s Chair Professor, and Deputy Head for Research and Graduate Studies of the NUS Department of Physics. His research centers on strongly correlated oxides, oxide interface physics, and two-dimensional quantum systems. Guided by a “materials-by-design” approach, he uses precise materials synthesis and interface engineering to investigate emergent quantum phenomena, including superconductivity and other exotic correlated electronic states.
Over the past decade, Ariando and his team have produced a series of original, internationally recognized advances in emergent quantum states in complex oxides, oxide superconductivity, and the growth and tuning of high-quality epitaxial thin films. Among their most notable breakthroughs is the discovery of superconductivity in rare-earth nickelate thin films with a transition temperature approaching 40 K under ambient pressure. This achievement challenged the long-standing dominance of cuprates and opened a new frontier in non-cuprate high-temperature superconductivity.
Beyond his research accomplishments, Ariando is also a dedicated and highly regarded mentor. He has trained numerous students and postdoctoral researchers who have gone on to hold independent positions at leading universities and research institutions around the world.
