The universality of the strange metal phase in many quantum materials is often attributed to the presence of a quantum critical point (QCP), a zero-temperature phase transition ruled by quantum fluctuations. In cuprates, where superconductivity hinders direct QCP observation, indirect evidence comes from the identification of fluctuations compatible with the strange metal phase. Here we show that the recently discovered charge density fluctuations (CDF) possess the right properties to be associated to a quantum phase transition. Using resonant x-ray scattering, we studied the CDF in two families of cuprate superconductors across a wide doping range (up to p = 0.22). At p* ≈ 0.19, the putative QCP, the CDF intensity peaks, and the characteristic energy Δ is minimum, marking a wedge-shaped region in the phase diagram indicative of a quantum critical behavior, albeit with anomalies. These findings strengthen the role of charge order in explaining strange metal phenomenology and provide insights into high-temperature superconductivity.
Signature of quantum criticality in cuprates by charge density fluctuations / Arpaia, R.; Martinelli, L.; Sala, M. M.; Caprara, S.; Nag, A.; Brookes, N. B.; Camisa, P.; Li, Q.; Gao, Q.; Zhou, X.; Garcia-Fernandez, M.; Zhou, K. -J.; Schierle, E.; Bauch, T.; Peng, Y. Y.; Di Castro, C.; Grilli, M.; Lombardi, F.; Braicovich, L.; Ghiringhelli, G.. - In: NATURE COMMUNICATIONS. - ISSN 2041-1723. - 14:1(2023), pp. 1-11. [10.1038/s41467-023-42961-5]
Signature of quantum criticality in cuprates by charge density fluctuations
Caprara S.Formal Analysis
;Di Castro C.Formal Analysis
;Grilli M.Formal Analysis
;
2023
Abstract
The universality of the strange metal phase in many quantum materials is often attributed to the presence of a quantum critical point (QCP), a zero-temperature phase transition ruled by quantum fluctuations. In cuprates, where superconductivity hinders direct QCP observation, indirect evidence comes from the identification of fluctuations compatible with the strange metal phase. Here we show that the recently discovered charge density fluctuations (CDF) possess the right properties to be associated to a quantum phase transition. Using resonant x-ray scattering, we studied the CDF in two families of cuprate superconductors across a wide doping range (up to p = 0.22). At p* ≈ 0.19, the putative QCP, the CDF intensity peaks, and the characteristic energy Δ is minimum, marking a wedge-shaped region in the phase diagram indicative of a quantum critical behavior, albeit with anomalies. These findings strengthen the role of charge order in explaining strange metal phenomenology and provide insights into high-temperature superconductivity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
