Discovery of pressure-induced bulk superconductivity in hybrid nNickelate La₅Ni₃O₁₁ single crystals -
Dr. Charles Zeng

New study from a team of scientists led by Dr. Qiaoshi (Charles) Zeng from HPSTAR and Prof. Xianhui Chen from the University of Science and Technology of China (USTC), has, for the first time, observed pressure-induced bulk superconductivity in hybrid nickelate La₅Ni₃O₁₁ single crystals by utilizing in situ high-pressure resistance and DC magnetic susceptibility measurement techniques under extreme conditions. The related research was published in Nature Physics.

Since the discovery of superconductivity at ~15 K in thin films with infinite-layer NiO₂ planes in 2019, nickel-based high-temperature superconductors, which represent the third class of unconventional high-Tc superconductors after cuprates and iron-based superconductors, have sparked intense research interest worldwide. Continuous breakthroughs have been achieved in recent years. For instance, in 2023, nearly 80 K superconductivity was discovered in bulk La₃Ni₂O₇ with bilayer NiO₂ under high pressure. In 2024, high-pressure-induced bulk superconductivity was also observed in bulk La₄Ni₃O₁₀ crystals with trilayer NiO₂ planes. However, superconductivity measurements in nickel-based superconductors have remained technically challenging, requiring very high pressure and strict hydrostatic conditions, which makes it extremely difficult to observe a zero-resistance signal with high-quality and clear Meissner effects—key signatures of superconductivity. These have severely hindered the discovery of new nickel-based superconductors and the understanding of their mechanisms.

To address these challenges, the research team led by Dr. Qiaoshi (Charles) Zeng has been focusing on the development of in-situ electrical transport and DC magnetization measurement techniques under hydrostatic high-pressure conditions. Overcoming a series of technical hurdles, they achieved in-situ characterization of both electrical and magnetic properties with high sensitivity and reproducibility at low temperatures under pressure, while ensuring the integrity of the single crystal structure. Previously, this team and collaborators provided the first key experimental evidence of bulk superconductivity in La₄Ni₃O₁₀ [Nature, 631, 531 (2024); Phys. Rev. X, 15, 021005 (2025); Adv. Mater., e07365 (2025)] and in Pr₄Ni₃O₁₀ [Phys. Rev. X, 15, 021008 (2025)]. They found that superconductivity in La₄Ni₃O₁₀ emerges only after the suppression of a density wave transition, whereas in Pr₄Ni₃O₁₀, the density wave and superconducting states could coexist, offering a solid experimental foundation for understanding the superconducting mechanism in trilayer nickelates.

In this latest study, the team and its collaborators again discovered zero resistance and a clear Meissner effect signal under high-pressure conditions in hybrid nickelate La₅Ni₃O₁₁ single crystals. They observed the most definitive Meissner signal reported to date in any nickel-based superconductor under high pressure. At ambient pressure, La₅Ni₃O₁₁ forms a unique hybrid structure composed of alternating superconducting La₃Ni₂O₇ layers and insulating La₂NiO₄ layers. It undergoes a density wave transition at ~170 K. With increasing pressure, the transition temperature of the density wave initially increases, but abruptly disappears at ~12 GPa, coinciding with the emergence of superconductivity. The superconducting transition temperature reaches its optimum at ~21 GPa. At optimal pressure, the onset superconducting transition temperature was ~64 K, with zero resistance at ~54 K. Correspondingly, a Meissner effect was observed at ~52.5 K, and the estimated superconducting volume fraction exceeded 70% (see Figure 1). The discovery of bulk superconductivity in La₅Ni₃O₁₁ under high pressure not only adds a new member to the nickelate superconductor family but also provides a new physical platform for investigating the intriguing mechanism of high-temperature superconductivity.

Figure 1. Pressure-Induced Bulk Superconductivity in Hybrid Nickelate La₅Ni₃O₁₁ Single Crystals. a. Crystal structure；b, Zero resistance under different applied magnetic fields and high pressure；c. Clear Meissner effect signals under high-pressure；d. P-T Phase diagram. Inset is a photomicrograph of a La₅Ni₃O₁₁ single crystal sample loaded with four probes in a diamond anvil cell. 

北京高压科学研究中心（上海分中心）、上海前瞻物质科学研究院的曾桥石研究员团队与中国科学技术大学陈仙辉院士团队合作，利用极端条件高等静压下的电阻和直流磁化率测量技术，首次在混合型镍酸盐La₅Ni₃O₁₁单晶中观测到了压力诱导的“体超导”现象。相关研究成果以“Pressure induced superconductivity in hybrid Ruddlesden‒Popper La₅Ni₃O₁₁ single crystals”为题于9月5日在《自然·物理》杂志上发表。