title: The phase diagram of electron-doped La(2-x)Ce(x)CuO(4-δ).
abstract: Superconductivity is a striking example of a quantum phenomenon in which electrons move coherently over macroscopic distances without scattering. The high-temperature superconducting oxides (cuprates) are the most studied class of superconductors, composed of two-dimensional CuO2 planes separated by other layers that control the electron concentration in the planes. A key unresolved issue in cuprates is the relationship between superconductivity and magnetism. Here we report a sharp phase boundary of static three-dimensional magnetic order in the electron-doped superconductor La(2-x)Ce(x)CuO(4-δ), where small changes in doping or depth from the surface switch the material from superconducting to magnetic. Using low-energy spin-polarized muons, we find that static magnetism disappears close to where superconductivity begins and well below the doping level at which dramatic changes in the transport properties are reported. These results indicate a higher degree of symmetry between the electron and hole-doped cuprates than previously thought.
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Saadaoui
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: Z
authors.initials: Z
authors.lastname: Salman
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Luetkens
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Prokscha
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Suter
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1.
authors.forename: W A
authors.initials: WA
authors.lastname: MacFarlane
authors.affiliation: Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: K
authors.initials: K
authors.lastname: Jin
authors.affiliation: Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Greene
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Morenzoni
authors.affiliation: Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1.
authors.forename: R F
authors.initials: RF
authors.lastname: Kiefl