Observation of metallic electronic structure in a single-atomic-layer oxide

• Published in: Nature communications Vol. 12; no. 1; p. 6171
• Main Authors: Sohn, Byungmin, Kim, Jeong Rae, Kim, Choong H., Lee, Sangmin, Hahn, Sungsoo, Kim, Younsik, Huh, Soonsang, Kim, Donghan, Kim, Youngdo, Kyung, Wonshik, Kim, Minsoo, Kim, Miyoung, Noh, Tae Won, Kim, Changyoung
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 26.10.2021; Nature Publishing Group UK; Nature Portfolio
• Subjects: Electronic structure; Epitaxy; Heterostructures; Insulators; Metal oxides; Metals; Monolayers; Oxides; Phases; Photoelectric emission; Thickness; Transition metal oxides
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-26444-z

Abstract Correlated electrons in transition metal oxides exhibit a variety of emergent phases. When transition metal oxides are confined to a single-atomic-layer thickness, experiments so far have shown that they usually lose diverse properties and become insulators. In an attempt to extend the range of electronic phases of the single-atomic-layer oxide, we search for a metallic phase in a monolayer-thick epitaxial SrRuO 3 film. Combining atomic-scale epitaxy and angle-resolved photoemission measurements, we show that the monolayer SrRuO 3 is a strongly correlated metal. Systematic investigation reveals that the interplay between dimensionality and electronic correlation makes the monolayer SrRuO 3 an incoherent metal with orbital-selective correlation. Furthermore, the unique electronic phase of the monolayer SrRuO 3 is found to be highly tunable, as charge modulation demonstrates an incoherent-to-coherent crossover of the two-dimensional metal. Our work emphasizes the potentially rich phases of single-atomic-layer oxides and provides a guide to the manipulation of their two-dimensional correlated electron systems.