Signatures of Polar Metal Phase in the Quasi-2D Electron System in PLD-Grown Amorphous-Epitaxial Oxide Heterostructures
For years, itinerant charge carriers in ferroelectric insulators were believed to completely quench ferroelectricity. Recent breakthroughs, however, demonstrated the existence of a novel class of quasi-two-dimensional polar metals with promising applications in nonvolatile electronics and spintronics. Here, by combining temperature-dependent magnetotransport measurements, optical second harmonic generation (SHG), resonant photoemission spectroscopy (ResPES), and X-ray absorption spectroscopy (XAS), we report on the properties of a BaTiO<sub>3</sub>-based oxide heterostructure, sustaining a persistent polar displacement in the BaTiO<sub>3</sub> layer while supporting a two-dimensional electron gas. This suggests that the oxide heterostructure may operate as a polar metal system, paving the way for new developments in oxide-based electronics.
Authors
- Alla Chikina (ORCID: https://orcid.org/0000-0003-3635-6503)
- M. Salluzzo (ORCID: https://orcid.org/0000-0001-8372-6963)
- Deepak Kumar (ORCID: https://orcid.org/0000-0002-5743-7129)
- A. Sambri (ORCID: https://orcid.org/0000-0003-1228-4226)
- F. Miletto Granozio (ORCID: https://orcid.org/0000-0002-9417-7848)
- Domenico Paparo (ORCID: https://orcid.org/0000-0002-7745-230X)
- Vladimir N. Strocov (ORCID: https://orcid.org/0000-0002-1147-8486)
- Yu Chen (ORCID: https://orcid.org/0000-0003-1651-3698)
- Martando Rath (ORCID: https://orcid.org/0000-0002-6736-6889)
- Federico Mazzola (ORCID: https://orcid.org/0000-0002-5380-4374)
- Marco Caputo (ORCID: https://orcid.org/0000-0001-7452-0998)
- Andrea Rubano (ORCID: https://orcid.org/0000-0002-9689-615X)
- Emiliano Di Gennaro (ORCID: https://orcid.org/0000-0003-4231-9776)
Institutions
- Paul Scherrer Institute (CH)
- Institute of Applied Science and Intelligent Systems (IT)
- Superconducting and other Innovative Materials and Devices Institute (IT)
- Istituto Nazionale di Fisica Nucleare, Sezione di Napoli (IT)
- Swiss Light Source
- University of Naples Federico II (IT)
Publication Details
- Journal
- Nano Letters
- Published
- 2025-08-31
- DOI
- https://doi.org/10.1021/acs.nanolett.5c03409
- Primary Topic
- Electronic and Structural Properties of Oxides
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- European Commission
- Ministero dell’Istruzione, dell’Università e della Ricerca
- HORIZON EUROPE Marie Sklodowska-Curie Actions
- HORIZON EUROPE European Innovation Council