Coexisting Ferroelectricity and Editable Superconducting Diode Effect at LaAlO₃/KTaO₃ interfaces

Yanwu Xie

School of Physics, Zhejiang University

Email: ywxie@zju.edu.cn

The LaAlO₃/KTaO₃ (LAO/KTO) interface has emerged as a versatile platform for exploring novel quantum phases and functional superconducting properties. In this talk, we present two distinct discoveries that highlight the rich physics of this system.

First, we report the coexistence of ferroelectricity and superconductivity at the LAO/KTO (111) interface [1]. We observe a universal enhancement of the superconducting transition temperature (T_c) by 0.2–0.6 K, accompanied by bistable transport hysteresis that signifies switchable ferroelectric polarization within the interfacial layer. This ferroelectric state, further confirmed by Raman spectroscopy and hysteresis loops below 50 K, modulates the interfacial potential well and enhances carrier confinement.

Second, we demonstrate a robust and editable superconducting diode effect (SDE) in LAO/KTO devices [2]. We observe rectification efficiencies up to 40% at 0.3 K. Utilizing conductive atomic force microscopy (c-AFM) lithography, we further showcase the ability to perform reversible nanoscale editing of the SDE’s polarity and efficiency by locally modifying the superconducting channel. These two findings collectively demonstrate the great potential of KTO-based interfaces for both fundamental physics and programmable superconducting electronics.

References:

[1] Meng Zhang, Ming Qin, Yanqiu Sun, Siyuan Hong, Yi Zhou, and Yanwu Xie, “Enhanced superconductivity and coexisting ferroelectricity at oxide interfaces”, Nat. Commun. 17, 219 (2026).

[2] Yishuai Wang, Wenze Pan, Meng Zhang, and Yanwu Xie, “KTaO₃-Based Editable Superconducting Diode”, Chin. Phys. Lett. 43, 010713 (2026).