Electric field control of superconductivity at the LaAlO3/KTaO3(111) interface

Zheng Chen; Yuan Liu; Hui Zhang; Zhongran Liu; He Tian; Yanqiu Sun; Meng Zhang; Yi Zhou; Jirong Sun; Yanwu Xie

doi:10.1126/science.abb3848

Electric field control of superconductivity at the LaAlO₃/KTaO₃(111) interface

Science. 2021 May 14;372(6543):721-724. doi: 10.1126/science.abb3848.

Authors

Zheng Chen^#¹, Yuan Liu^#¹, Hui Zhang^#², Zhongran Liu³, He Tian³, Yanqiu Sun¹, Meng Zhang¹, Yi Zhou^{4

5

6}, Jirong Sun^{4

5

7}, Yanwu Xie^{8

9}

Affiliations

¹ Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, China.
² School of Integrated Circuit Science and Engineering, Beihang University, Beijing, 100191, China.
³ Center of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
⁴ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China. yizhou@iphy.ac.cn jrsun@iphy.ac.cn ywxie@zju.edu.cn.
⁵ Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China.
⁶ Kavli Institute for Theoretical Sciences and CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China.
⁷ School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
⁸ Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, and Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, China. yizhou@iphy.ac.cn jrsun@iphy.ac.cn ywxie@zju.edu.cn.
⁹ Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.

^# Contributed equally.

PMID: 33986177
DOI: 10.1126/science.abb3848

Abstract

The oxide interface between LaAlO₃ and KTaO₃(111) can harbor a superconducting state. We report that by applying a gate voltage (V _G) across KTaO₃, the interface can be continuously tuned from superconducting into insulating states, yielding a dome-shaped T _c-V _G dependence, where T _c is the transition temperature. The electric gating has only a minor effect on carrier density but a strong one on mobility. We interpret the tuning of mobility in terms of change in the spatial profile of the carriers in the interface and hence, effective disorder. As the temperature is decreased, the resistance saturates at the lowest temperature on both superconducting and insulating sides, suggesting the emergence of a quantum metallic state associated with a failed superconductor and/or fragile insulator.

Publication types

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