Solid-State Electrochemical Switch of Superconductor-Metal-Insulators

Xi Zhang; Gowoon Kim; Qian Yang; Jiake Wei; Bin Feng; Yuichi Ikuhara; Hiromichi Ohta

doi:10.1021/acsami.1c17014

Solid-State Electrochemical Switch of Superconductor-Metal-Insulators

ACS Appl Mater Interfaces. 2021 Nov 17;13(45):54204-54209. doi: 10.1021/acsami.1c17014. Epub 2021 Nov 4.

Authors

Xi Zhang¹, Gowoon Kim², Qian Yang², Jiake Wei³, Bin Feng³, Yuichi Ikuhara³, Hiromichi Ohta¹

Affiliations

¹ Research Institute for Electronic Science, Hokkaido University, N20W10, Kita, Sapporo 001-0020, Japan.
² Graduate School of Information Science and Technology, Hokkaido University, N14W9, Kita, Sapporo 060-0814, Japan.
³ Institute of Engineering Innovation, The University of Tokyo, 2-11-16 Yayoi, Bunkyo, Tokyo 113-8656, Japan.

PMID: 34734522
DOI: 10.1021/acsami.1c17014

Abstract

Controlling the oxygen content can manipulate the electrical conductivity of transition metal oxides (TMOs). Although the superconductor-metal-insulator transition is useful for functional devices, an electrical path must be developed to manipulate the oxygen deficiency (δ) while maintaining the solid state. YBa₂Cu₃O_7-δ (YBCO, 0 ≤ δ ≤ 1) is a high transition temperature (T_c) TMO that can be modulated from a superconductor (T_c ≈ 92 K when δ = 0) to an insulator (δ ≈ 1). Here, we show a simple and efficient way to manipulate δ in YBCO films using a solid-state electrochemical redox treatment. Applying a negative voltage injects oxide ions to the YBCO films, increasing T_c. Employing a positive voltage suppresses the superconducting transition and modulates the electrical conductivity. The present results demonstrate that the superconductor-metal-insulator transition of YBCO is modulated electrochemically in the solid state, opening possibilities of superconducting oxide-based device applications.

Keywords: YBa2Cu3O7−δ; electrochemical redox reaction; oxygen deficiency; superconductor−metal−insulator transition; yttria-stabilized zirconia.