Ionic-Bond-Driven Atom-Bridged Room-Temperature Cooper Pairing in Cuprates and Nickelates: a Theoretical Framework Supported by 32Experimental Evidences

摘要

针对铜氧化物和镍氧化物中高温超导的配对机制这一长期难题，本文基于离子键在eV量级的主导作用、O^-和O^2-的电子亲和能（分别为1.46 eV和-8.08 eV）以及金属原子较大的双电子电离能（约15–28 eV），提出了氧（O）桥连电子对（e^--O-e^-）或金属（M）桥连空穴对（h⁺-M-h⁺）的巡游库珀对图像。该配对在赝隙温度T*高于T_c时形成，遵循化学键→结构→性质的关系，并适用于铜氧化物、镍氧化物、铁基及其他离子型超导体。作者通过32项不同的实验证据，尤其是CuO₂面内的STM图像与极小配对尺寸，证实了该机制的正确性与普适性，并指出任何亚eV或共价键合配对机制均不可靠。该理论揭示了离子键与超导电性之间的缺失环节，解决了长达40年的困惑，并验证了在离子键超导体中实现室温载流子配对的可行性。在此基础上，作者建立了以最强配对强度和玻色-爱因斯坦凝聚为核心的新理论框架，为理解高温超导机理开辟了新路径，并使室温超导的梦想更近一步。

材料

• YBa₂Cu₃O₇
• Bi₂Sr₂CaCu₂O₈
• La₃Ni₂O₇
• La₂PrNi₂O₇

方法

• theoretical analysis based on ionic bonding
• charge sum rule
• comparison with STM images
• calculation of screened Coulomb repulsion

关键词

• ionic bond
• cooper pair
• oxygen bridged pairing
• metal bridged pairing
• pseudogap
• bose einstein condensation
• d wave symmetry
• charge stripe
• room temperature superconductivity

亮点

• This mechanism is applicable to cuprates, nickelates, iron-based and other new ionic superconductors.
• The STM image in the CuO₂ plane combining with the small pair size serves as an ironclad proof.
• An_y other sub-eV and covalent-binding pairing mechanisms would be doubtful.
• The theory reveals that room-temperature Cooper pairing is feasible in ionic-bonded superconductors.

结论

• We propose an innovative idea of electron e- (hole h+) pairing bridged by oxygen O (metal M) atoms, i.e., the ionic-bond-driven e- -O- e- (h+ -M- h+) itinerant Cooper pairing.
• Its correctness and universality are confirmed by 32 diverse experimental evidences.
• Our findings provide the missing link between ionic bonding and superconductivity, resolve a 40-year puzzle and validate the feasibility of room-temperature carrier-pairing in ionic superconductors.

主要论断

• Ionic-bond-driven oxygen-bridged electron pairs (e^--O-e^-) and metal-bridged hole pairs (h⁺-M-h⁺) are the universal Cooper pairing mechanism in cuprates, nickelates, and other ionic superconductors.
  • 证据: abstract: 'we propose a groundbreaking idea of electron e^- (hole h⁺) pairing bridged by oxygen O (metal M) atoms',full_text: 'the ionic-bond-driven e^--O-e^- (h⁺-M-h⁺) itinerant Cooper pairing formed at pseudogap temperature T* > T_c'
• The proposed pairing mechanism is supported by 32 diverse experimental evidences, especially STM images of hole stripes along Cu-O-Cu chains and small Cooper pair size.
  • 证据: abstract: 'correctness and universality are confirmed by 32 diverse experimental evidences, especially, the STM image in the CuO₂ plane combining with the small Cooper-pair size',full_text Fig. 4a shows STM constant-current topographic image of hole stripe phase
• An_y sub-eV pairing mechanism (e.g., magnetic or electron-phonon) cannot overcome the eV-scale Coulomb repulsion between two holes in a Cooper pair; eV-scale ionic bonds are required.
  • 证据: full_text Fig. 3 shows calculated screened Coulomb repulsion ≈2.63 eV for two holes at 1.5 Å,abstract: 'An_y other sub-eV and covalent-binding pairing mechanisms would be doubtful'
• The eV-scale ionic bonding enables Cooper pair formation above T_c or even at room temperature, potentially enabling room-temperature superconductivity if coherent condensation is achieved.
  • 证据: full_text: 'the eV-scale ionic bonds… ensure that Cooper pairs can be formed above T_c or even at room temperature',abstract: 'validate the feasibility of room-temperature carrier-pairing in ionic-bonded superconductors'

研究流程

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