Ionic Liquid Gating Induced Protonation of Electron-Doped Cuprate Superconductors

Mohsin Rafique; Zhongpei Feng; Zefeng Lin; Xinjian Wei; Menghan Liao; Ding Zhang; Kui Jin; Qi-Kun Xue

doi:10.1021/acs.nanolett.9b02776

Ionic Liquid Gating Induced Protonation of Electron-Doped Cuprate Superconductors

Nano Lett. 2019 Nov 13;19(11):7775-7780. doi: 10.1021/acs.nanolett.9b02776. Epub 2019 Nov 4.

Authors

Mohsin Rafique¹, Zhongpei Feng^{2

3}, Zefeng Lin^{2

3}, Xinjian Wei^{2

3}, Menghan Liao¹, Ding Zhang^{1

4

5}, Kui Jin^{2

3}, Qi-Kun Xue^{1

4

5}

Affiliations

¹ State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics , Tsinghua University , Beijing 100084 , China.
² Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China.
³ School of Physical Sciences , University of Chinese Academy of Sciences , Beijing 100049 , China.
⁴ Beijing Academy of Quantum Information Sciences , Beijing 100193 , China.
⁵ Frontier Science Center for Quantum Information , Beijing 100084 , China.

PMID: 31664842
DOI: 10.1021/acs.nanolett.9b02776

Abstract

Ion injection controlled by electric field has attracted growing attention due to its tunability over bulk-like materials. Here, we achieve protonation of an electron-doped high-temperature superconductor, La_2-xCe_xCuO₄, by gating in the electrochemical regime of the ionic liquid. Such a process induces a superconductor-insulator transition together with the crossing of the Fermi surface reconstruction point. Applying negative voltages not only can reverse the protonation process but also recovers superconductivity in samples deteriorated by moisture in the ambient. Our work extends the application of electric-field-induced protonation into high-temperature cuprate superconductors.

Keywords: High-temperature superconductivity; cuprate; electric-double-layer transistor; ionic liquid; protonation.

Publication types

Research Support, Non-U.S. Gov't