Correlated Insulator at the Surface of the Polar Metal Ca 3 Ru 2 O 7
Year: 2026
Type: article
Abstract: We investigate the electronic structure at the surface of the correlated oxide Ca_{3}Ru_{2}O_{7}, a low-symmetry ruthenate oxide which hosts an unconventional polar-metal phase. From a combination of angle-resolved photoemission spectroscopy and scanning tunneling spectroscopy measurements, we demonstrate that the surface hosts an insulating phase, a distinct departure from metallicity within the bulk. Utilizing quantitative low-energy electron diffraction in conjunction with electronic structure calculations, we show how this results from a combined surface structure relaxation and the impact of marked electronic correlations in this system. Our findings highlight the proximity of Ca_{3}Ru_{2}O_{7} to an insulating metallic state, and illustrate how subtle structural distortions can control its emergent electronic phases.
Source: Physical Review Letters
DOI: 10.1103/x9gh-xxwb
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Funders: Diamond Light Source, UK Research and Innovation, Leverhulme Trust, University of Edinburgh, VINNOVA, Svenska Forskningsrådet Formas, Vetenskapsrådet, International Max Planck Research School for Chemistry and Physics of Quantum Materials, Engineering and Physical Sciences Research Council, Japan Society for the Promotion of Science
OpenAlex ID: W7140770669