Abstract
Interfaces can differ from their parent compounds in charge, spin, and orbital orders, providing fertile ground for emergent phenomena, strongly correlated physics, and novel device applications. Here, we present evidence of a ferroelectric order at the interface of two oxides, amorphous LaAlO3/KTaO3(111), where two seemingly mutually exclusive orders—ferroelectricity and superconductivity—coexist. Ferroelectricity is confirmed through scanning transmission electron microscopy (STEM), second harmonic generation (SHG) microscopy, and piezoelectric force microscopy (PFM). STEM reveals a displacement of K atoms relative to Ta atoms, facilitated by oxygen vacancies at the LAO/KTO interface. The resulting ferroelectric polarization is locally switchable by applying a voltage between the PFM tip and the LaAlO3 film. Flipping ferroelectric polarization reduces interfacial conductivity by more than 1000 times, simultaneously suppresses superconductivity. Moreover, the ferroelectric hysteresis correlates with hysteretic changes in interfacial conductivity and the superconducting transition temperature (Tc), providing clear evidence of coupling between ferroelectricity and superconductivity. These findings open a pathway to ferroelectric superconductivity with broken inversion symmetry and non-volatile control of superconductivity.
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The data that support the findings of this study and all other relevant data are provided with this paper and are also available via the Figshare repository at https://doi.org/10.6084/m9.figshare.30889256
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Acknowledgements
This work was supported by National Key R&D Program of China (No. 2023YFA1406400 and No. 2024YFA1408102 to J.W.), Research Center for Industries of the Future (RCIF project No. WU2023C001 to J.W.) at Westlake University, the National Natural Science Foundation of China (Grant No. 12174318 to J.W.), the Zhejiang Provincial Natural Science Foundation of China (Grant No. XHD23A2002 to J.W.). We acknowledge the assistance provided by Dr. Qike Jiang of the Instrumentation and Service Center for Physical Sciences and the Instrumentation and Service Centers for Molecular Science at Westlake University.
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The film synthesis and lithography were done by M.Z., STEM, SHG, PFM and electrical transport measurements were done by M.D.D. and X.B.C., and the analysis and interpretation put forward by J.W.
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Dong, M.D., Cheng, X.B., Zhang, M. et al. Strongly coupled interface ferroelectricity and interface superconductivity in amorphous LaAlO3/KTaO3(111). Nat Commun (2026). https://doi.org/10.1038/s41467-026-69641-4
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DOI: https://doi.org/10.1038/s41467-026-69641-4
