Orbital inversion and emergent lattice dynamics in infinite layer CaCoO2
The layered cobaltate CaCoO2 exhibits a unique herringbone-like structure. Serving as a potential prototype for a new class of complex lattice patterns, we study the properties of CaCoO2 using X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). Our results reveal a significant inter-plane hybridization between the Ca 4s- and Co 3d- orbitals, leading to an inversion of the textbook orbital occupation of a square planar geometry. Further, our RIXS data reveal a strong low energy mode, with anomalous intensity modulations as a function of momentum transfer close to a quasi-static response. These findings indicate that the newly discovered herringbone structure exhibited in CaCoO2 may serve as a promising laboratory for the design of materials having strong electronic, orbital and lattice correlations.
Authors
- Stefano Agrestini (ORCID: https://orcid.org/0000-0002-3625-880X)
- Zhi‐Xun Shen (ORCID: https://orcid.org/0000-0002-1454-0281)
- Harold Y. Hwang (ORCID: https://orcid.org/0000-0002-9230-3214)
- Daniel Jost (ORCID: https://orcid.org/0000-0001-7327-7789)
- Ke‐Jin Zhou (ORCID: https://orcid.org/0000-0001-9293-0595)
- Eder G. Lomeli (ORCID: https://orcid.org/0000-0002-8141-2140)
- Thomas Devereaux (ORCID: https://orcid.org/0000-0001-8072-9237)
- Wei-Sheng Lee (ORCID: https://orcid.org/0000-0001-7677-0421)
- Emily Been (ORCID: https://orcid.org/0000-0002-2246-7336)
- Matteo Rossi (ORCID: https://orcid.org/0000-0002-4254-0713)
- Brian Moritz (ORCID: https://orcid.org/0000-0002-3747-8484)
- Chunjing Jia (ORCID: https://orcid.org/0000-0001-7999-1932)
- Woo Jin Kim (ORCID: https://orcid.org/0000-0002-6787-3522)
Institutions
- SLAC National Accelerator Laboratory (US)
- Diamond Light Source (GB)
- Stanford University (US)
Publication Details
- Journal
- npj Quantum Materials
- Published
- 2025-06-16
- DOI
- https://doi.org/10.1038/s41535-025-00778-z
- Citations
- 2
- Primary Topic
- Magnetic and transport properties of perovskites and related materials
- Type
- article
- Field-Weighted Citation Impact
- 0.85
Funders
- U.S. Department of Energy
- Gordon and Betty Moore Foundation
- Alexander von Humboldt-Stiftung
- Diamond Light Source
- National Energy Research Scientific Computing Center
- Office of Science
- Basic Energy Sciences