A selective control of volatile and non-volatile superconductivity in an insulating copper oxide via ionic liquid gating

Sci Bull (Beijing). 2020 Oct 15;65(19):1607-1613. doi: 10.1016/j.scib.2020.05.013. Epub 2020 May 19.

Abstract

Manipulating the superconducting states of high transition temperature (high-Tc) cuprate superconductors in an efficient and reliable way is of great importance for their applications in next-generation electronics. Here, employing ionic liquid gating, a selective control of volatile and non-volatile superconductivity is achieved in pristine insulating Pr2CuOδ (PCO) films, based on two distinct mechanisms. Firstly, with positive electric fields, the film can be reversibly switched between superconducting and non-superconducting states, attributed to the carrier doping effect. Secondly, 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 phenomenon represents a distinctive route of manipulating superconductivity in PCO, resulting from the doping healing of oxygen vacancies in copper-oxygen planes as unravelled by high-resolution scanning transmission electron microscope and in situ X-ray diffraction experiments. The effective manipulation of volatile/non-volatile superconductivity in the same parent cuprate brings more functionalities to superconducting electronics, as well as supplies flexible samples for investigating the nature of quantum phase transitions in high-Tc superconductors.

Keywords: Electron-doped copper oxide; Ionic liquid gating; Parent cuprate; Superconducting thin film; Volatile and non-volatile superconductivity.