Evidence for a Quantum Phase Transition inPr2−xCexCuO4−δfrom Transport Measurements

Abstract

The doping and temperature dependences of the Hall coefficient, $R_H$, and ab-plane resistivity in the normal state down to 350 mK is reported for oriented films of the electron-doped high-$T_c$ superconductor ${\mathrm{Pr}}_{2-x}{\mathrm{Ce}}_x{\mathrm{CuO}}_{4-\delta }$. The doping dependences of $\beta$ ($\rho ={\rho }_0+A{T}^{\beta }$) and $R_H$ (at 350 mK) suggest a quantum phase transition at a critical doping near $x=0.165$.