Correlation of strontium anharmonicity with charge-lattice dynamics of the apical oxygens and their coupling to cuprate superconductivity
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Published:2024-01-08
Issue:2
Volume:37
Page:025005
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ISSN:0953-2048
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Container-title:Superconductor Science and Technology
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language:
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Short-container-title:Supercond. Sci. Technol.
Author:
Conradson Steven D,
Velasco VictorORCID,
Silva Neto Marcello BORCID,
Jin Chang-Qing,
Li Wen-Min,
Cao Li-Peng,
Gauzzi AndreaORCID,
Karppinen MaaritORCID,
Perali Andrea,
Wimberger SandroORCID,
Bishop Alan R,
Baldinozzi GianguidoORCID,
Latimer Matthew,
Gilioli Edmondo
Abstract
Abstract
By means of Cu K edge x-ray absorption spectra of overdoped high-pressure oxygenated superconducting
Y
S
r
2
C
u
2.75
M
o
0.25
O
7.54
and
S
r
2
C
u
O
3.3
, we demonstrate a remarkably strong three way correlation between the superconductivity and the local dynamics of their highly anharmonic Cu–Sr and Cu-apical O pairs. We model the latter as aspects of the Internal Quantum Tunneling Polarons (IQTPs) that give the two-site distributions in extended x-ray absorption fine structure and inelastic pair distribution function measurements. This finding obviates the common assumption that the universal Ba/Sr-apical O dielectric layer, far from only maintaining the separation of charges between the charge reservoir and the
C
u
O
2
conducting domains, plays an unexpectedly active role in the unusual electronic properties of cuprate superconductors. Furthermore, we investigate the effects of the dynamic structure associated with these pairs by means of the exact diagonalization of a prototype Hamiltonian based on a six-atom cluster, with two neighboring Cu-apical O pairs bridged by an anharmonically coupled Sr atom and a planar O atom. In terms of the Kuramoto model for synchronization, these calculations show a first order phase transition, driven by anharmonicity, to a synchronized state of the IQTPs, in which a fraction of the charge originally confined to the apical O sites is transferred onto the planar O in the superconducting plane. This combination of experimental results and theory demonstrates that the Ba/Sr-apical O layer of cuprates most likely plays an important role in high temperature superconductivity via its collective charge dynamics.
Funder
National Science and Technology Major Project
National Recovery and Resilience Plan
Basic Energy Sciences
National Natural Science Foundation of China
Javna Agencija za Raziskovalno Dejavnost RS
National Science Foundation
Subject
Materials Chemistry,Electrical and Electronic Engineering,Metals and Alloys,Condensed Matter Physics,Ceramics and Composites