Metallic state in La-doped YBa$_2$Cu$_3$O$_y$ thin films with n-type charge carriers
ORAL
Abstract
Through substitution of La for Ba and reduction of oxygen, we successfully doped n- and p-type charge carriers into La-doped YBa$_2$Cu$_3$O$_y$ thin films synthetized by pulsed laser deposition technique. The n-type samples demonstrated metallic behaviors and in-plane resistivity exhibited a quadratic temperature dependence within the metallic regime, and then evolved into a ln T-dependence insulating-like state. Furthermore, the doping evolution of temperature with minimum resistivity (T$_{min}$) and electron-electron rate were investigated and showed asymmetry between p- and n-side. The present results suggest the potential of obtaining n-type superconductivity in La-doped YBa$_2$Cu$_3$O$_y$ and investigating n-p asymmetry (symmetry) in cuprates with the same crystallographic structure.
*We thank National Research Foundation (NRF) Singapore under the Competitive Research Program (CRP) ``Tailoring Oxide Electronics by Atomic Control'' NRF2008NRF-CRP002-024 and Ministry of Education (MOE) FRC-ARF Grant No. R-144-000-278-112.
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