We examine various possibilities for the pairing mechanisms in the recently discovered bilayer-nickelate superconductor within the Bardeen-Cooper-Schrieffer framework. Unlike earlier studies, where only a pure $d$-wave or sign-changing $s$-wave superconductivity instability was investigated, our study explores the possibilities of mixed-state superconducting instability such as the one involving both $d$- and sign-changing $s$-waves. While assuming that the superconductivity arises because of the magnetic correlations, we examine the nature of the superconducting gap function associated density of states with various possible magnetic correlation wavevectors arising out as a result of multiple pockets owing to the multiple orbitals and bilayer splitting. We also explore the effect of differences in the nature of Fermi surfaces suggested by various studies.
Motivated by recent experimental studies on superconductivity found in nickelate-based materials, we study the temperature dependence of the spin correlation and the superconducting pairing interaction within an effective two-band Hubbard model by the quantum Monte Carlo method. Based on parameters extracted from first-principles calculations, our intensive numerical results reveal that the pairing with a $d_{xy}$-wave symmetry firmly dominates over other pairings at low temperature, which is mainly determined by the Ni 3$d$ orbital. It is also found that the effective pairing interaction is e…
Fermi liquid and isotropic superconductivity of Hund scenario for bilayer nickelates
Hangzhou Normal University（杭州师范大学）；Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；Songshan Lake Materials Laboratory（松山湖材料实验室）
Selective suppression of electronic orders via interlayer coupling in superconducting bilayer nickelate thin films
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所凝聚态物理国家实验室）；University of Chinese Academy of Sciences（中国科学院大学）；Department of Physics, The Chinese University of Hong Kong（香港中文大学物理系）；Hefei National Laboratory（合肥国家实验室）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）；State Key Laboratory of Quantum Information Technologies and Materials, The Chinese University of Hong Kong（香港中文大学量子信息技术与材料国家重点实验室）
Infinite-layer nickelates present a new family of potential unconventional superconductors. A key open question is the superconducting pairing symmetry. We present low-temperature measurements of the London penetration depth in optimally doped La_{0.8}Sr_{0.2}NiO_{2}, Pr_{0.8}Sr_{0.2}NiO_{2}, and Nd_{0.8}Sr_{0.2}NiO_{2}. For La and Pr-nickelates, the superfluid density shows a quadratic temperature dependence, indicating nodal superconductivity in the presence of disorder. Nd-nickelate exhibits complex low-temperature behavior, which we attribute to magnetic impurities. These results are consi…
Squeezing dynamical singlets in bilayer nickelates
Center for Computational Quantum Physics, Flatiron Institute（Flatiron研究所计算量子物理中心）；Department of Physics, Columbia University（哥伦比亚大学物理系）；Université Paris-Saclay, CNRS, CEA, Institut de physique théorique（巴黎萨克雷大学、法国国家科学研究中心、法国原子能和替代能源委员会、理论物理研究所）
A unified theory of thin film and bulk bilayer nickelates
School of Physics, Hangzhou Normal University（杭州师范大学物理学院）；Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所北京凝聚态物理国家研究中心）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）
Evidence for Clean d-wave Superconductivity in Samarium Nickelates
The State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry & Chemical Engineering, Xiamen University（厦门大学化学化工学院固体表面物理化学国家重点实验室）；School of Physics, University of Electronic Science and Technology of China（电子科技大学物理学院）；State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China（电子科技大学电子薄膜与集成器件国家重点实验室）；State Key Laboratory of Cryogenic Science and Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences（中国科学院理化技术研究所低温科学与技术国家重点实验室）
Interlayer Five-Spin Polaron in Superconducting Bilayer Nickelates
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory（斯坦福材料能源科学研究所，SLAC国家加速器实验室）；Department of Physics, Stanford University（斯坦福大学物理系）；National Synchrotron Light Source II, Brookhaven National Laboratory（美国国家同步辐射光源II，布鲁克海文国家实验室）；Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory（斯坦福同步辐射光源，SLAC国家加速器实验室）；Advanced Light Source, Lawrence Berkeley National Laboratory（先进光源，劳伦斯伯克利国家实验室）；Canadian Light Source（加拿大光源）；Department of Physics, University of Florida（佛罗里达大学物理系）；Department of Materials Science and Engineering, Stanford University（斯坦福大学材料科学与工程系）
We report theoretical predictions on the pairing symmetry of the newly discovered superconducting nickelate Nd$_{1-x}$Sr$_{x}$NiO$_{2}$ based on the renormalized mean-field theory for a generalized model Hamiltonian proposed in [Phys. Rev. B \textbf{101}, 020501(R)]. For practical values of the key parameters, we find a transition between a gapped ($d+is$)-wave pairing state in the small doping region to a gapless $d$-wave pairing state in the large doping region, accompanied by an abrupt Fermi surface change at the critical doping. Our overall phase diagram also shows the possibility of a ($d…
Layer-Asymmetry-Induced Topological Superconductivity in High-T$_c$ Bilayer Nickelates
Hong Kong University of Science and Technology（香港科技大学）；RIKEN Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS)（理化学研究所交叉理论与数学科学中心）；Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所理论物理重点实验室）；School of Physics, Beijing Institute of Technology（北京理工大学物理学院）
Electronic structure, dimer physics, orbital-selective behavior, and magnetic tendencies in the bilayer nickelate superconductor La$_3$Ni$_2$O$_7$ under pressure
基于{\it ab initio}技术，研究了双层La$_3$Ni$_2$O$_7$在压力下的电子结构与磁性，揭示了其由$d_{3z^2-r^2}$轨道形成的二聚体晶格、双轨道最小模型、异常的轨道间跃迁及主导的自旋条纹序。
Single-crystal structural phase diagram of stoichiometric bilayer nickelate La3Ni2O7 under hydrostatic pressure
The University of Tokyo（东京大学）；RIKEN Center for Emergent Matter Science (CEMS)（理化学研究所 新兴物质科学中心）；Tohoku University（东北大学）；Japan Synchrotron Radiation Research Institute (JASRI)（日本同步辐射研究所）；Tokyo College, The University of Tokyo（东京大学东京学院）；Institute of Engineering Innovation, The University of Tokyo（东京大学工程创新研究所）；RIKEN Pioneering Research Institute (PRI)（理化学研究所 先驱研究 institute）
Ionic-Bond-Driven Atom-Bridged Room-Temperature Cooper Pairing in Cuprates and Nickelates: a Theoretical Framework Supported by 32 Experimental Evidences
