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arXiv · 2310.03863

Visualising emergent phenomena at oxide interfaces

Michael Oberaigner·Manuel Ederer·Sandeep Kumar Chaluvadi·Pasquale Orgiani·Regina Ciancio·Stefan Löffler·Gerald Kothleitner·Daniel Knez
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Abstract

Knowledge of atomic-level details of structure, chemistry, and electronic states is paramount for a comprehensive understanding of emergent properties at oxide interfaces. We utilise a novel methodology based on atomic-scale electron energy loss spectroscopy (EELS) to spatially map the electronic states tied to the formation of a two-dimensional electron gas (2DEG) at the prototypical non-polar/polar $TiO_2$/$LaAlO_3$ interface. Combined with differential phase contrast analysis we directly visualise the microscopic locations of ions and charge and find that 2DEG states and $Ti^{3+}$ defect states exhibit different spatial distributions. Supported by density functional theory (DFT) and inelastic scattering simulations we examine the role of oxygen vacancies in 2DEG formation. Our work presents a general pathway to directly image emergent phenomena at interfaces using this unique combination of arising microscopy techniques with machine learning assisted data analysis procedures.

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Michael Oberaigner, Manuel Ederer, Sandeep Kumar Chaluvadi, Pasquale Orgiani, Regina Ciancio, Stefan Löffler, Gerald Kothleitner, Daniel Knez. 2023-10-05. Visualising emergent phenomena at oxide interfaces. https://arxiv.org/abs/2310.03863

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