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Understanding the interplay between charge order (CO) and other phenomena (for example, pseudogap, antiferromagnetism, and superconductivity) is one of the central questions in the cuprate high-temperature superconductors. The discovery that similar forms of CO exist in both hole- and electron-doped cuprates opened a path to determine what subset of the CO phenomenology is universal to all the cuprates. We use resonant x-ray scattering to measure the CO correlations in electron-doped cuprates (La2−xCexCuO4 and Nd2−xCexCuO4) and their relationship to antiferromagnetism, pseudogap, and superconductivity. Detailed measurements of Nd2−xCexCuO4 show that CO is present in the x = 0.059 to 0.166 range and that its doping-dependent wave vector is consistent with the separation between straight segments of the Fermi surface. The CO onset temperature is highest between x = 0.106 and 0.166 but decreases at lower doping levels, indicating that it is not tied to the appearance of antiferromagnetic correlations or the pseudogap. Near optimal doping, where the CO wave vector is also consistent with a previously observed phonon anomaly, measurements of the CO below and above the superconducting transition temperature, or in a magnetic field, show that the CO is insensitive to superconductivity. Overall, these findings indicate that, although verified in the electron-doped cuprates, material-dependent details determine whether the CO correlations acquire sufficient strength to compete for the ground state of the cuprates.
Bibliographical noteFunding Information:
We thank Helmholtz-Zentrum Berlin for the allocation of synchrotron radiation beamtime. We thank Y. Jiang for his assistance to sample characterization and preparation. This work was supported by the Canadian Institute for Advanced Research (CIFAR) Global Academy (E.H.d.S.N.); the Max Planck–University of British Columbia Centre for Quantum Materials (E.H.d.S.N. and A.D.); the Killam, Alfred P. Sloan, and Natural Sciences and Engineering Research Council of Canada’s (NSERC’s) Steacie Memorial Fellowships (A.D.); the Alexander von Humboldt Fellowship (A.D. and M.M.); the Canada Research Chairs Program (A.D. and G.A.S.); and the NSERC, Canada Foundation for Innovation (CFI), and CIFAR Quantum Materials. The work at the University of Minnesota was supported partially by NSF Award 1006617 and by the NSF through the University of Minnesota Materials Research Science and Engineering Center under award no. DMR-1420013. Work at the University of Maryland was supported by NSF grant DMR-1410665. The beamline REIXS of the Canadian Light Source is funded by CFI, NSERC, National Research Council Canada, Canadian Institutes of Health Research, the government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan.
2016 © The Authors.
- charge density waves
- High-temperature superconductivity
- resonant x-ray scattering
How much support was provided by MRSEC?
Reporting period for MRSEC
- Period 3
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.