The polar discontinuity picture in nickelate superlattices: comparison of the insulating and metallic phases
Abstract
We present a first-principles study of the formal-charge polar discontinuity in superlattices of BaTiO3 interfaced with SmNiO3 or BiNiO3, comparing the results for the insulating and metallic nickelate phases. Polar discontinuities arising from differently charged layers in perovskites are well-studied in heterostructures such as LaAlO3/SrTiO3, and recently, signatures consistent with such a polar discontinuity have been observed in systems where the formally charged layers would reside in a metal. We first identify signatures of the polar discontinuity in the structure and the density of states of superlattices with BaTiO3 and insulating BiNiO3, and find partial screening by modification of the BiNiO3 charge disproportionation pattern analogous to our previous study on BaTiO3/SmNiO3. We then examine superlattices constructed from the corresponding metallic nickelate phases and find that, despite the presence of screening charges, the qualitative interfacial response is remarkably similar to that of the insulating counterparts. We show that the metallic screening charges have little influence on the apparent formal-charge polar discontinuity and discuss practical limitations of the polar-discontinuity picture when interpreting and quantifying screening at metallic nickelate/ferroelectric interfaces.
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BibTeX
@misc{simmen2026polar,
title = {{The polar discontinuity picture in nickelate superlattices: comparison of the insulating and metallic phases}},
author = {Edith Simmen and Jonathan Amara and Philippe Ghosez and Nicola A. Spaldin},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.08067},
eprint = {2611.08067},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.08067},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The polar discontinuity picture in nickelate superlattices: comparison of the insulating and metallic phases
AU - Edith Simmen
AU - Jonathan Amara
AU - Philippe Ghosez
AU - Nicola A. Spaldin
PY - 2026
DA - 2026/11/05
PB - arXiv
DO - 10.48550/arxiv.2611.08067
UR - https://arxiv.org/abs/2611.08067
AB - We present a first-principles study of the formal-charge polar discontinuity in superlattices of BaTiO_3 interfaced with SmNiO_3 or BiNiO_3, comparing the results for the insulating and metallic nickelate phases. Polar discontinuities arising from differently charged layers in perovskites are well-studied in heterostructures such as LaAlO_3/SrTiO_3, and recently, signatures consistent with such a polar discontinuity have been observed in systems where the formally charged layers would reside in a metal. We first identify signatures of the polar discontinuity in the structure and the density of states of superlattices with BaTiO_3 and insulating BiNiO_3, and find partial screening by modification of the BiNiO_3 charge disproportionation pattern analogous to our previous study on BaTiO_3/SmNiO_3. We then examine superlattices constructed from the corresponding metallic nickelate phases and find that, despite the presence of screening charges, the qualitative interfacial response is remarkably similar to that of the insulating counterparts. We show that the metallic screening charges have little influence on the apparent formal-charge polar discontinuity and discuss practical limitations of the polar-discontinuity picture when interpreting and quantifying screening at metallic nickelate/ferroelectric interfaces.
ER -