发表机构
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences; University of Chinese Academy of Sciences; Department of Physics, The Chinese University of Hong Kong; Hefei National Laboratory; Deutsches Elektronen-Synchrotron DESY; State Key Laboratory of Quantum Information Technologies and Materials, The Chinese University of Hong Kong（中国科学院物理研究所凝聚态物理国家实验室; 中国科学院大学; 香港中文大学物理系; 合肥国家实验室; 德国电子同步加速器; 香港中文大学量子信息技术与材料国家重点实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过氧退火与等价稀土取代施加c轴压力，抑制双层镍酸盐薄膜的SDW转变温度，实现超导并选择性消除类电荷有序，揭示层间耦合对电子有序态的调控机制。
AI 中文摘要
自旋密度波（SDW）有序在双层镍酸盐中的发现，加剧了人们对其与超导性相互作用的兴趣。与铜氧化物中掺杂迅速抑制奈尔温度不同，双层镍酸盐中的SDW转变温度（$T_{\mathrm{SDW}}$）对氧退火具有鲁棒性，甚至在压力下还会升高。在此，我们将氧退火与等价稀土（$A$位）取代相结合，有效施加$c$轴单轴压力，实现了$T_{\mathrm{SDW}}$从150 K降至70 K的超导双层镍酸盐薄膜。值得注意的是，虽然SDW有序被削弱但仍然存在，第二种类电荷的各向异性有序在超导态中被完全消除。偏振分辨的O $K$边X射线吸收和电子结构计算表明，增强的层间耦合重构了费米面并削弱了SDW。这些发现与自旋-无自旋条纹基态一致，为密度波形成机制及其与超导性的相互作用提供了新的见解。
英文摘要
The discovery of spin-density-wave (SDW) order in bilayer nickelates has intensified interest in its interplay with superconductivity. Unlike cuprates, where doping rapidly suppresses the Néel temperature, the SDW transition temperature ($T_{\mathrm{SDW}}$) in bilayer nickelates is robust against oxygen annealing and even increases under pressure. Here, we combine oxygen annealing with isovalent rare-earth ($A$-site) substitution to effectively apply $c$-axis uniaxial pressure, realizing superconducting bilayer nickelate films with $T_{\mathrm{SDW}}$ suppressed from 150 K to 70 K. Notably, while SDW order is weakened but remains, a second charge-like anisotropy order is completely eliminated in the superconducting state. Polarization-resolved O $K$-edge X-ray absorption and electronic structure calculations show that strengthened interlayer coupling reconstructs the Fermi surface and weakens the SDW. These findings, consistent with a spin-spinless stripe ground state, provide new insight into the mechanism of density wave formation and their interplay with superconductivity.
