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Abstract The mechanism of unconventional superconductivity in correlated materials remains a great challenge in condensed matter physics. The recent discovery of superconductivity in infinite-layer nickelates, as an analog to high-Tccuprates, has opened a new route to tackle this challenge. By growing 8 nm Pr0.8Sr0.2NiO2films on the (LaAlO3)0.3(Sr2AlTaO6)0.7substrate, we successfully raise the superconducting onset transition temperatureTcin the widely studied SrTiO3-substrated nickelates from 9 K into 15 K, which indicates compressive strain is an efficient protocol to further enhance superconductivity in infinite-layer nickelates. Additionally, the x-ray absorption spectroscopy, combined with the first-principles and many-body simulations, suggest a crucial role of the hybridization between Ni and O orbitals in the unconventional pairing. These results also suggest the increase ofTcbe driven by the change of charge-transfer nature that would narrow the origin of general unconventional superconductivity in correlated materials to the covalence of transition metals and ligands.
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Absence of 3a0 charge density wave order in the infinite-layer nickelate NdNiO2
Abstract A hallmark of many unconventional superconductors is the presence of many-body interactions that give rise to broken-symmetry states intertwined with superconductivity. Recent resonant soft X-ray scattering experiments report commensurate 3a0charge density wave order in infinite-layer nickelates, which has important implications regarding the universal interplay between charge order and superconductivity in both cuprates and nickelates. Here we present X-ray scattering and spectroscopy measurements on a series of NdNiO2+xsamples, which reveal that the signatures of charge density wave order are absent in fully reduced, single-phase NdNiO2. The 3a0superlattice peak instead originates from a partially reduced impurity phase where excess apical oxygens form ordered rows with three-unit-cell periodicity. The absence of any observable charge density wave order in NdNiO2highlights a crucial difference between the phase diagrams of cuprate and nickelate superconductors.
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- PAR ID:
- 10568198
- Publisher / Repository:
- Nature
- Date Published:
- Journal Name:
- Nature Materials
- Volume:
- 23
- Issue:
- 4
- ISSN:
- 1476-1122
- Page Range / eLocation ID:
- 486 to 491
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1038/s41563-024-01797-0
