• Accepted Paper

Electronic structure of an artificial two-dimensional polar metal

Jiachang Bi, Tian-Yu Sun, Xiaoran Liu, Mikhail Kareev, Ruyi Zhang, Zhen Wang, Liang-Feng Huang, Yanwei Cao, and Jak Chakhalian

Phys. Rev. B - Accepted 16 September, 2026

DOI: https://doi.org/10.1103/4xp6-nlns

Abstract

Polar metals, a category of materials exhibiting the unexpected coexistence of polar structural distortion and metallicity, have attracted considerable research interest. Despite several experimental studies, the effect of polar distortions on the electronic structure (such as orbital configuration) of polar metals remains unclear. Here, we investigate the electronic band structure, crystal-field splitting, and orbital configuration of an artificial two-dimensional polar metal based on the BaTiO3/SrTiO3/LaTiO3 heterostructure. The interfacial crystal and electronic structures were investigated by scanning transmission electron microscopy with atomic layer–resolved electron energy-loss spectroscopy. Resonant X-ray Linear Dichroism spectra revealed an anomalous orbital configuration with a unique sequence (dxy < dxz/dyz < d3z2r2 < dx2y2), where the in-plane and out-of-plane orbital sequence of the t2g and eg states is reversed. More importantly, the t2g orbitals are nearly degenerate, which is a characteristic feature of polar distortion. The nearly degenerate t2g orbitals and the altered orbital sequence arise from the competition between epitaxial strain and polar distortion. Our work demonstrates that the electronic structure of polar metals can be strongly modulated by polar distortions, providing a general route for designing quantum states with tailored orbital configurations.

Export citation

Export citation

Choose format for download:

Download Citation

If the author has provided any supplemental materials with this article they will be available upon publication of the version of record.

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation