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Exploring charge and spin fluctuations in infinite-layer cuprate SrCuO2 from a phonon perspective
The infinite-layer cuprate A CuO 2 ( A = Ca, Sr, Ba) possesses the simplest crystal structure among numerous cuprate superconductors and can serve as a prototypical system to explore the unconventional superconductivity. Based on the first-principles electronic structure calculations, we have studie...
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Published in: | Science China. Physics, mechanics & astronomy mechanics & astronomy, 2024-08, Vol.67 (8), p.287411, Article 287411 |
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Main Authors: | , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites |
Online Access: | Get full text |
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Summary: | The infinite-layer cuprate
A
CuO
2
(
A
= Ca, Sr, Ba) possesses the simplest crystal structure among numerous cuprate superconductors and can serve as a prototypical system to explore the unconventional superconductivity. Based on the first-principles electronic structure calculations, we have studied the electronic and magnetic properties of the infinite-layer cuprate SrCuO
2
from a phonon perspective. We find that interesting fluctuations of charges, electrical dipoles, and local magnetic moments can be induced by the atomic displacements of phonon modes in SrCuO
2
upon the hole doping. Among all optical phonon modes of SrCuO
2
in the antiferromagnetic Néel state, only the
A
1
g
mode that involves the full-breathing O vibrations along the Cu-O bonds can cause significant fluctuations of local magnetic moments on O atoms and dramatic charge redistributions between Cu and O atoms. Notably, due to the atomic displacements of the
A
1
g
mode, both the charge fluctuations on Cu and the electrical dipoles on O show a dome-like evolution with increasing hole doping, quite similar to the experimentally observed behavior of the superconducting
T
c
; in comparison, the fluctuations of local magnetic moments on O display a monotonic enhancement along with the hole doping. Further analyses indicate that around the optimal doping, there exists a large softening in the frequency of the
A
1
g
phonon mode and a van Hove singularity in the electronic structure close to the Fermi level, suggesting potential electron-phonon coupling. Our work reveals the important role of the full-breathing O phonon mode playing in the infinite-layer SrCuO
2
, which may provide new insights in understanding the cuprate superconductivity. |
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ISSN: | 1674-7348 1869-1927 |
DOI: | 10.1007/s11433-024-2388-y |