Quantum fluctuations of charge order induce phonon softening in a superconducting cuprate

Abstract

Quantum phase transitions play an important role in shaping the phase diagram of high-temperature cuprate superconductors. These cuprates possess intertwined orders which interact strongly with superconductivity. However, the evidence for the quantum critical point associated with the charge order in the superconducting phase remains elusive. Here we show the short-range charge orders and the spectral signature of the quantum fluctuations in La${}_{2-x}$Sr${}_x$CuO${}_4$ (LSCO) near the optimal doping using high-resolution resonant inelastic X-ray scattering. On performing calculations through a diagrammatic framework, we discovered that the charge correlations significantly soften several branches of phonons. These results elucidate the role of charge order in the LSCO compound, providing evidence for quantum critical scaling and discommensurations associated with charge order.

9 pages, 4 figures

References in corpus (9)

• Theory of Intertwined Orders in High Temperature Superconductors
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• Dispersive charge density wave excitations and temperature dependent commensuration in Bi2Sr2CaCu2O8+δ
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Cited by in corpus (5)

• Signature of quantum criticality in cuprates by charge density fluctuations
• Fate of charge order in overdoped La-based cuprates
• Exciton dynamics uncovering electron fractionalization in superconducting cuprates
• Robust charge-density wave correlations in the electron-doped single-band Hubbard model
• Low-energy quasi-circular electron correlations with charge order wavelength in ${\text{Bi}}_2{\text{Sr}}_2\text{Ca}{\text{Cu}}_2{\text{O}}_{8+\delta }$