Electrochemical Tuning of YBa₂Cu₃O_7-x Transport Properties in Superconducting Transistor-like Structure

The ground state of strongly-correlated oxide superconductors is strongly dependent on the oxygen stoichiometry, which allows tuning the superconducting phase through a controlled motion of oxygen ions. Depositing a more electronegative layer on top of the superconducting material, in a transistor-like geometry, allows for a reversible electrochemical modulation of the oxygen content via redox chemical reactions, paving the way for novel field-effect switching superconducting devices. In this work, we explore such effects in planar devices based on the high-temperature cuprate superconductor YBa₂Cu₃O_7-x, in which oxygen diffusion is controlled via an aluminium gate. We will show that, upon gating, the gate and source-drain conductance as well as the superconducting critical temperature are modulated between non-volatile states in either a reversible/irreversible fashion depending on the Al and YBa₂Cu₃O_7-x thickness.