  Manipulating the superconducting states of high-T_c cuprate superconductors
in an efficient and reliable way is of great importance for their applications
in next-generation electronics. Traditional methods are mostly based on a
trial-and-error method that is difficult to implement and time consuming. Here,
employing ionic liquid gating, a selective control of volatile and non-volatile
superconductivity is achieved in pristine insulating Pr_2CuO_{4\pm\delta} film,
based on two distinct mechanisms: 1) with positive electric fields, the film
can be reversibly switched between non-superconducting and superconducting
states, attributed to the carrier doping effect. 2) The film becomes more
resistive by applying negative bias voltage up to -4 V, but strikingly, a
non-volatile superconductivity is achieved once the gate voltage is removed.
Such a persistent superconducting state represents a novel phenomenon in copper
oxides, resulting from the doping healing of oxygen vacancies in copper-oxygen
planes as unraveled by high-resolution scanning transmission electron
microscope and in-situ x-ray diffraction experiments. The effective
manipulation and mastering of volatile/non-volatile superconductivity in the
same parent cuprate opens the door to more functionalities for superconducting
electronics, as well as supplies flexible samples for investigating the nature
of quantum phase transitions in high-T_c superconductors.
