Quantum Criticality in Electron-Doped La$_{2-x}$Ce$_{x}$CuO$_{4}$

ORAL

Abstract

We studied the in-plane resistivity of over-doped La$_{2-x}$Ce$_ {x}$CuO$_{4}$ thin films as a function of temperature (down to 20 mK) and in magnetic fields of up to 17 T. In zero field, we found a $\rho \sim T$ region above $T_{c}$ for superconducting films and a $\rho \sim T^{2}$ region for non-superconducting films as $T\rightarrow 0$. The boundaries of $\rho \sim T $ and $\rho \sim T^{2}$ regions merge at a critical doping $x=0.175\pm 0.005$, which is also the boundary of the superconducting dome. In magnetic fields, the $\rho \sim T$ to $\rho \sim T^{2}$ transition as $T\rightarrow 0$ is shifted to lower doping with increasing field. We compare these results to related behavior in hole-doped cuprates [1] and to a recent phase diagram proposed by Sachdev [2].\\[4pt] [1] R.A. Cooper \textit{et al.}, Science \textbf{323}, 603 (2009).\\[0pt] [2] S. Sachdev, http://arxiv.org/abs/0907.0008V7 (2009).

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Authors

  • Kui Jin

    University of Maryland, Physics Department, Center for Nanophysics \& Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA

  • Nicholas Butch

    University of Maryland, Physics Department, University of Maryland, College Park, UC San Diego, Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, Center for Nanophysics \& Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA, Center for Nano Physics and Advanced Materials, Department of Physics, University of Maryland, University of Maryland

  • Gabriel Droulers

    Center for Nanophysics \& Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA

  • K. Kirshenbaum

    University of Maryland, Physics Department, Center for Nanophysics \& Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA, Center for Nanophysics and Advanced Materials, University of Maryland, Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, Center for Nano Physics and Advanced Materials, Department of Physics, University of Maryland, University of Maryland, College Park, Center for Nanophysics and Advanced Materials

  • Xiaohang Zhang

    Center for Nanophysics \& Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA

  • Paul Bach

    University of Maryland, Physics Department, Center for Nanophysics \& Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA, Center for Nanophysics and Advanced Materials, University of Maryland

  • J. Paglione

    University of Maryland, College Park, University of Maryland, Center for Nanophysics \& Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA, Center for Nanophysics and Advanced Materials, University of Maryland, Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, Center for Nano Physics and Advanced Materials, Department of Physics, University of Maryland, University of Maryland, College Park, Center for Nanophysics and Advanced Materials

  • Richard Greene

    University of Maryland, Physics Department, Physics, U. Maryland, Center for Nanophysics \& Advanced Materials and Department of Physics, University of Maryland, College Park, MD 20742, USA, Center for Nanophysics and Advanced Materials, University of Maryland