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Thermodynamic signatures of quantum criticality in cuprates
- Source :
- Nature 567, 218 (2019)
- Publication Year :
- 2018
-
Abstract
- The three central phenomena of cuprate superconductors are linked by a common doping $p^{\star}$, where the enigmatic pseudogap phase ends, around which the superconducting phase forms a dome, and at which the resistivity exhibits an anomalous linear dependence on temperature as $T \to 0$. However, the fundamental nature of $p^{\star}$ remains unclear, in particular whether it marks a true quantum phase transition. We have measured the specific heat $C$ of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range across $p^{\star}$. As a function of doping, we find that the electronic term $C_{\rm el}$ is strongly peaked at $p^{\star}$, where it exhibits a $-T$log$T$ dependence as $T \to 0$. These are the classic signatures of a quantum critical point, as observed in heavy-fermion and iron-based superconductors where their antiferromagnetic phase ends. We conclude that the pseudogap phase of cuprates ends at a quantum critical point, whose associated fluctuations are most likely involved in the $d$-wave pairing and the anomalous scattering.<br />Comment: Includes Supplementary Information
Details
- Database :
- arXiv
- Journal :
- Nature 567, 218 (2019)
- Publication Type :
- Report
- Accession number :
- edsarx.1804.08502
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1038/s41586-019-0932-x