Paper

Daily Overview: This post sorts papers by relevance to nickelate superconductors. Summaries are AI-generated and may contain errors. arXiv submission processing window: times are unavailable (UTC). 1. Perpendicular electric field induced $s^\pm$-wave to $d$-wave superconducting transition in thin film La$_3$Ni$_2$O$_7$ Relevance Score: 5.4135 Authors: Yongping Wei, Xun Liu, Fan Yang, Mi Jiang Link: http://arxiv.org/abs/2604.07185v1 Summary: Inspired by the vertically electric-field-tunable superconducting properties of Ruddlesden–Popper bilayer nickelate La₃Ni₂O₇, this study employs the dynamic cluster quantum Monte Carlo method to solve the imbalanced two-orbital bilayer Hubbard model. By analyzing the electric-field-induced pairing symmetry and its evolution under undoped, hole-doped, and electron-doped conditions, we find that the s±-wave pairing originating from the d_{z²} orbital is suppressed, while the interlayer mismatch of the d_{z²} orbital and the transfer of electrons to the d_{x²-y²} orbital drive a pairing symmetry transition from s±-wave to d-wave. Interestingly, the d-wave pairing arising from the d_{x²-y²} orbital exhibits a dome-shaped behavior as a function of electric field strength. The large-scale many-body calculations are consistent with the predictions of weak-coupling methods, providing new insights into the superconducting mechanism of RP nickelates. ...

arXiv Daily: nickelate superconductors 2026-04-08

Daily Overview: This post sorts papers by relevance to nickelate superconductors. Summaries are AI-generated and may contain errors. arXiv submission processing window: times are unavailable (UTC). 1. Tunable superconductivity and spin density wave in La3Ni2O7/LaAlO3 thin films Relevance Score: 5.7793 Authors: Yu-Han Cao, Kai-Yue Jiang, Hong-Yan Lu, Da Wang, Qiang-Hua Wang Link: http://arxiv.org/abs/2604.05590v1 Summary: Using first-principles calculations and the singular-mode functional renormalization group method, we systematically investigate the effect of interlayer nickel-nickel distance on the ground state in La₃Ni₂O₇/LaAlO₃ thin films. The results show that a smaller interlayer distance leads to a C-type spin density wave (interlayer ferromagnetic coupling), while a larger interlayer distance yields a G-type spin density wave (interlayer antiferromagnetic coupling). Between these two phases, an s±-wave superconducting state emerges, dominated by pairing in the Ni 3d₃z²⁻ᵣ² orbital. This finding explains the origin of superconductivity observed in the thin films under ambient pressure and predicts that applying pressure will suppress the superconducting transition temperature until the system enters the C-type spin density wave. If confirmed experimentally, this prediction will provide deep insight into the nature of electronic correlations in this system, as the C-type spin density wave naturally emerges within the itinerant electron picture, whereas it is difficult to realize within the local magnetic moment picture (where interlayer spins remain antiferromagnetically coupled). ...

arXiv Daily: nickelate superconductors 2026-04-07

Daily Overview: This post sorts papers by relevance to nickelate superconductors. Summaries are AI-generated and may contain errors. arXiv submission processing window: times are unavailable (UTC). 1. Collective spin excitations in trilayer nickelate La$_4$Ni$_3$O$_{10}$ Relevance Score: 5.2877 Authors: Ying Chan, Yuehong Li, Yujie Yan, Xunyang Hong, Tianren Wang, Marli dos Reis Cantarino, Yinghao Zhu, Enkang Zhang, Lixing Chen, Jun Okamoto, Hsiao-Yu Huang, Di-Jing Huang, N. B. Brookes, Johan Chang, Yao Shen, Jun Zhao, Qisi Wang Link: http://arxiv.org/abs/2604.04643v1 Summary: Resonant inelastic X-ray scattering (RIXS) at the Ni L edge on single crystals of the trilayer nickelate La4Ni3O10 reveals collective spin excitations with a bandwidth of approximately 60 meV, comparable to that of the bilayer nickelate La3Ni2O7, but with significantly reduced spectral weight, indicating weaker electronic correlations in the trilayer system. Localized spin excitations at around 100 and 200 meV are also observed, originating from local dipole and quadrupole excitations. The dispersive magnetic excitations exhibit three-dimensional characteristics, and fitting with linear spin-wave theory yields comparable in-plane and out-of-plane exchange coupling parameters, with the interlayer coupling being the strongest. The results indicate that La4Ni3O10 possesses stronger three-dimensional magnetism, with its spin dynamics consistent with spin-density-wave order, while the reduced electronic correlations and three-dimensional multi-orbital character are key factors leading to differences in its magnetic excitation spectrum compared to the bilayer nickelate, providing important insights into the evolution of magnetism and its connection to superconductivity in the Ruddlesden-Popper nickelate family. ...

arXiv Daily: nickelate superconductors 2026-04-06

Daily Overview: This post sorts papers by relevance to nickelate superconductors. Summaries are AI-generated and may contain errors. arXiv submission processing window: times are unavailable (UTC). 1. High-energy electronic excitations in La3Ni2O7 by time-resolved optical spectroscopy Relevance Score: 5.6279 Authors: Junzhi Zhu, Mengwu Huo, Yubin Wang, Yuxin Zhai, Lili Hu, Haiyun Huang, Xiu Zhang, Baixu Xiang, Mengdi Zhang, Yusong Gan, Zhiyuan An, Meng Wang, Qihua Xiong, Haiyun Liu Affiliations: Tsinghua University, Collaborative Innovation Center of Quantum Matter, Beijing Academy of Quantum Information Sciences, Sun Yat-Sen University, Chinese Academy of Sciences, Frontier Science Center for Quantum Information, University of Chinese Academy of Sciences Link: http://arxiv.org/abs/2604.02843v1 Summary: This study employs time-resolved optical spectroscopy to investigate the ultrafast dynamics of high-energy electronic excitations in bilayer nickelate La₃Ni₂O₇ from 10 K to room temperature at ambient pressure. Two high-energy electronic excitations originating from distinct interband transitions are identified at approximately 1.8 eV and 2.4 eV, revealing different density wave (DW) gaps of about 54 meV and 67 meV, respectively. The relaxation dynamics of these two excited states are well described by the Rothwarf-Taylor model. Additionally, four coherent Raman-active phonon modes are observed, exhibiting varying coupling strengths to the different electronic excitations. The phonon softening upon heating from about 100 K to room temperature can be explained by a semi-quantitative model incorporating thermal expansion and anharmonic phonon-phonon coupling, while the deviation of measured phonon frequencies from the model fit at low temperatures suggests an additional contribution from electron-phonon coupling. This work directly demonstrates the complex gap structure and phonon dynamics in this material, providing key insights into its density wave mechanism and many-body effects. ...

arXiv Daily: nickelate superconductors 2026-04-03

Daily Overview: This post sorts papers by relevance to nickelate superconductors. Summaries are AI-generated and may contain errors. arXiv submission processing window: times are unavailable (UTC). 1. Dissecting superconductivity in the Ruddlesden-Popper nickelates: The role of electron correlation and interlayer magnetic exchange Relevance Score: 5.7332 Authors: Xiaoyang Chen, Zezhong Li, Mei Xie, Deyuan Hu, Yiu-Fung Chiu, Stefano Agrestini, Wenliang Zhang, Yi Lu, Meng Wang, Mirian Garcia-Fernandez, Donglai Feng, Ke-Jin Zhou Link: http://arxiv.org/abs/2604.01902v1 Summary: This study employs resonant inelastic X-ray scattering (RIXS) to directly compare the electronic and magnetic excitation properties of trilayer nickelate La₄Ni₃O₁₀ and bilayer La₃Ni₂O₇. The results show that La₄Ni₃O₁₀ exhibits more itinerant behavior, evidenced by broader Ni d-d orbital excitations and a stronger fluorescence background, indicating weaker electronic correlations than in the bilayer system. Despite the weaker correlations, clear collective spin excitations are observed, including dispersive acoustic and optical magnon branches as well as incommensurate spin density waves (SDW). Using linear spin-wave theory analysis, the interlayer superexchange interaction Jz is extracted to be approximately 22 meV, significantly smaller than that in La₃Ni₂O₇. The weaker electron correlations and reduced interlayer magnetic exchange together account for the substantially lower superconducting transition temperature of the trilayer compound (about 30 K) compared to the bilayer (about 80 K). This study establishes interlayer magnetic coupling and electronic correlations as key parameters for superconductivity in layered nickelates, providing important constraints for understanding the superconducting pairing mechanism in this emerging family. ...

arXiv Daily: nickelate superconductors 2026-04-02