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Daily Overview: Today’s highlight focuses on deepening the understanding of the electronic structure in hybrid Ruddlesden-Popper nickelates. In [1], a study based on ¹³⁹La nuclear quadrupole resonance (NQR) reveals the intricate intertwining of charge density wave (CDW) and spin density wave (SDW) in the trilayer nickel oxide La₄Ni₃O₁₀. The experiment finds that the density wave transition is first-order in nature and exhibits an incommensurate order. Strong spin fluctuations above the transition temperature indicate a coupling mechanism between CDW and SDW. This work provides key experimental evidence for understanding the microscopic origin of density wave states and their relationship with the superconducting phase in nickel-based superconductors. arXiv submission processing window: 2026-01-25 02:46 to 2026-01-25 02:46 UTC. ...

arXiv Daily: nickelate superconductors 2026-01-25

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. Structural stability, electronic structure, and magnetic properties of the single-layer trilayer La3Ni2O7 polymorph Relevance Score: 5.9469 Authors: Shekhar Sharma, Yi-Feng Zhao, Antia S. Botana Link: http://arxiv.org/abs/2601.15858v1 Summary: This study systematically investigates the structural stability, electronic structure, and magnetic properties of the alternating monolayer-trilayer (1313) stacked La₃Ni₂O₇ polymorphs using first-principles calculations and group theory analysis. At ambient pressure, the highest-symmetry Cmmm structure exhibits multiple unstable phonon branches at high-symmetry points in the Brillouin zone, and the corresponding distortions can lead to another experimentally reported space group Imma, which features NiO₆ octahedral tilting. Magnetic analysis indicates that the electronic structure of this material at ambient pressure is predominantly governed by the trilayer block, whereas the monolayer block is in a Mott insulating state. Under pressure, the tetragonal P4/mmm structure becomes stable, consistent with experimental observations. The study reveals that octahedral tilting is not a prerequisite for superconductivity and elucidates the symmetry relationships among different space groups as well as the pressure-driven structural phase transition mechanism. ...

arXiv Daily: nickelate superconductors 2026-01-22

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. Spin Fluctuations in the Rare-Earth Doped Bilayer Nickelates Relevance Score: 5.5834 Authors: Honglin Zhou, Xinman Ye, Gang Wang, Devashibhai Adroja, David Tam, Michael Marek Koza, Zhilun Lu, Jinguang Cheng, Dao-Xin Yao, Huiqian Luo Link: http://arxiv.org/abs/2601.14946v2 Summary: The spin fluctuations in rare-earth Pr and Nd doped bilayer nickelates La₂LnNi₂O₇₋δ (Ln = La, Pr, Nd) were investigated under ambient pressure using inelastic neutron scattering. In the undoped La₃Ni₂O₇₋δ, a flat spin fluctuation mode at 45 meV was observed; upon doping, this mode splits into two modes at 43 and 48 meV, with an additional weak mode appearing at approximately 60 meV. Notably, the spin fluctuation intensity in La₂NdNi₂O₇₋δ is significantly higher than that in La₃Ni₂O₇₋δ and La₂PrNi₂O₇₋δ. These results are consistent with a description based on the stripe-type antiferromagnetic Heisenberg model, indicating that rare-earth doping enhances the interlayer magnetic coupling, with the interlayer exchange coupling SJ⊥ increasing from about 60 meV to 69–73 meV, while the intralayer coupling remains weak (≤3.5 meV). This enhancement may account for the increase in superconducting transition temperature from 80 K to near 100 K following rare-earth doping. This work reveals the regulatory role of rare-earth doping on spin dynamics and superconducting pairing in bilayer nickelates. ...

arXiv Daily: nickelate superconductors 2026-01-21

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. Superconductor-insulator transitions in infinite-layer nickelates controlled via ${operando}$ monitored reduction Relevance Score: 5.3023 Authors: Heng Wang, Haoliang Huang, Wei Lv, Xianfeng Wu, Guangdi Zhou, Zihao Nie, Yueying Li, Cui Ding, Danfeng Li, Hongtao Yuan, Qi-Kun Xue, Zhuoyu Chen Affiliations: Tsinghua University, Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area, City University of Hong Kong, Southern University of Science and Technology, Nanjing University Link: http://arxiv.org/abs/2601.14072v1 Summary: By developing an in situ monitoring reduction (OMR) method, this study achieved continuous modulation of the Ni 3d orbital electron occupancy in infinite-layer nickelate superconductors over an ultra-wide range from approximately 3d⁷ to 3d⁹, thereby controllably driving the superconductor-insulator transition (SIT). Combining synchrotron X-ray absorption spectroscopy and scanning transmission electron microscopy analysis of oxygen atoms, the electron occupancy states were precisely calibrated, and the SIT was further modulated using ionic liquid gating and magnetic fields. Nernst effect measurements reveal that, unlike in cuprates, pairing initiates as soon as the resistance starts to drop, while the Meissner effect only appears in the zero-resistance state, marking the establishment of global phase coherence. Angle-dependent magnetotransport studies show that within the transition temperature range, superconductivity exhibits a mixture of two-dimensional and three-dimensional characteristics, indicating that the observed SIT deviates from the classical 2D model. These results provide a unique perspective for understanding the interplay between structural and electronic phase transitions in infinite-layer nickelates within the oxygen content–magnetic field–temperature parameter space. ...

arXiv Daily: nickelate superconductors 2026-01-20

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. Spin-density-wave transition in monolayer-trilayer La3Ni2O7 single crystals Relevance Score: 6.1872 Authors: Mingxin Zhang, Jie Dou, Di Peng, Cuiying Pei, Qi Wang, Yi Zhao, Chao Xiong, Shuo Li, Jun Luo, Juefei Wu, Lingxiao Zhao, Qing Zhang, Jie Yang, Yulin Chen, Jinkui Zhao, Wenge Yang, Hanjie Guo, Qiaoshi Zeng, Rui Zhou, Yanpeng Qi Affiliations: ShanghaiTech University, Center for High Pressure Science and Technology Advanced Research, Great Bay University, Chinese Academy of Sciences, Songshan Lake Materials Laboratory Link: http://arxiv.org/abs/2601.13090v1 Summary: This study successfully synthesized high-quality, long-range ordered hybrid 1313-type La₃Ni₂O₇ single crystals (with an alternating monolayer-trilayer structure) and systematically characterized their physical properties. At ambient pressure, the material exhibits typical semiconducting behavior and displays distinct anomalies in resistivity, magnetic susceptibility, and specific heat at 170 K. ¹³⁹La nuclear magnetic resonance spectroscopy unambiguously confirms that these anomalies originate from a spin-density wave (SDW) transition. High-pressure electrical transport measurements indicate that the application of pressure can induce metallization; however, no superconductivity is observed up to 65 GPa. These findings establish hybrid 1313-type La₃Ni₂O₇ as a new member of the Ruddlesden-Popper nickelate family featuring a unique SDW transition, offering a platform for investigating the interplay among crystal structure, electronic order, and superconductivity in hybrid nickelates. ...

arXiv Daily: nickelate superconductors 2026-01-19