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arXiv · 2610.07878

Negative charging energy in LaAlO$_3$/SrTiO$_3$ quantum dots induced by SrTiO$_3$ polarization

J. Czarnecki·A. Sierant·B. Szafran·P. Szumniak·T. S. Jespersen·G. Meucci·T. Jansen·R. Citro·A. Maiellaro·N. Bergeal·M. Bibes·M. Saluzzo·A. Kalaboukhov·P. Wójcik
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Abstract

We propose a microscopic mechanism for the negative charging energy in LaAlO$_3$/SrTiO$_3$ quantum dots, arising from the electrostatic image charge associated with the paraelectric response of SrTiO$_3$. Using a self-consistent configuration-interaction approach that accounts for both Coulomb repulsion and image-charge interactions, we find a robust regime of electron pairing whose strength is tunable through the confinement potential and the effective image-charge distance, set by the thickness of the interfacial two-dimensional electron gas. Our results establish dielectric image-charge effects as a route to controllable electron pairing in oxide quantum dots and other materials with a strong dielectric response.

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J. Czarnecki, A. Sierant, B. Szafran, P. Szumniak, T. S. Jespersen, G. Meucci, T. Jansen, R. Citro, A. Maiellaro, N. Bergeal, M. Bibes, M. Saluzzo, A. Kalaboukhov, P. Wójcik. 2026-10-06. Negative charging energy in LaAlO$_3$/SrTiO$_3$ quantum dots induced by SrTiO$_3$ polarization. https://arxiv.org/abs/2610.07878

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