Ferroelectric enhancement of superconductivity in thin films of the electron doped Cuprate Pr_2-xCe_xCuO_4-δ

We deposit a thin film of the non-superconducting under-doped electron-doped cuprate Pr_1.89Ce_0.11CuO_4-δ on Strontium Titanate (STO) and on ferroelectric 1\% Calcium-substituted Strontium Titanate substrates. We see superconductivity in the films grown on ferroelectric substrates in contrast with those grown on standard substrates. The latter ones remain insulating down to the lower temperature reached. We also observe a hysteretic behavior of the resistivity versus gate voltage in the samples deposited on ferroelectric substrates, which is suppressed by a magnetic field of a few Teslas. In films deposited on non-ferroelectric STO, we observe hysteresis in the resistivity in the presence of an external out-of-plane magnetic field, which we hypothesize to be related to magnetostrictive effects.