We present experimental results for the in-plane resistivity of the electron-doped cuprate superconductor $\mathrm{L}{\mathrm{a}}_{2-x}\mathrm{C}{\mathrm{e}}_x\mathrm{Cu}{\mathrm{O}}_4$ above its transition temperature $T_c$ as a function of Ce doping $x$ and temperature. For the doping $x$ between 0.11 and 0.17, where $T_c$ varies from 30 K ($x=0.11$) to 5 K ($x=0.17$), we find that the resistivity shows a $T^2$ behavior for all values of doping over the measurement range from 70 to 250 K. The coefficient of the $T^2$ resistivity term decreases with increasing $x$ following the trend in $T_c$. We analyze our data theoretically and posit that $n$-type cuprates are better thought of as strange metals. Although the quadratic temperature dependence appears to be in naive agreement with the Fermi-liquid (FL) expectations, the facts that the measured resistivity is large and approximate $T^2$ scattering dominates the resistivity even up to 400 K argue against a standard normal-metal FL picture being applicable. We discuss possible origins of the strange-metal behavior.

• Received 29 May 2018
• Revised 30 October 2018

DOI:https://doi.org/10.1103/PhysRevB.98.224503