Realization of strongly correlated 2D honeycomb boron
Borophene, a two-dimensional (2D) boron sheet, has recently gained considerable attention as a postgraphene material owing to its unique properties, such as intrinsic metallic character, lightest element monolayer structure, and high-frequency phonons. These features, together with its theoretically predicted high density of states, make borophene an excellent platform for investigating various quantum phenomena. However, the realization of emergent phenomena is hindered by fabrication challenges and inherently weak electronic correlations within the s and p electron system. Here, we demonstrate a strongly correlated 2D electronic state derived from a honeycomb boron lattice exposed at the surface of ternary boride LaRh 3 B 2 . Using angle-resolved photoemission spectroscopy, we uncover the extended saddle-point van Hove singularity near the Fermi level, which is linked to the substantial lattice expansion and many-body interaction. Moreover, scanning tunneling microscopy reveals the electronic nematicity, which likely originates from the saddle-point instability. Our findings open a pathway to exploring the exotic correlated phenomena in boron-based 2D systems.
Authors
- F. Fortuna (ORCID: https://orcid.org/0000-0002-7063-1890)
- A. Antezak (ORCID: https://orcid.org/0009-0009-3161-7365)
- S. Souma (ORCID: https://orcid.org/0000-0003-2460-4602)
- T Takahashi
- K. Ozawa (ORCID: https://orcid.org/0000-0003-2157-4671)
- Hiroshi Kumigashira (ORCID: https://orcid.org/0000-0003-4668-2695)
- Pedro Henrique Rezende Gonçalves (ORCID: https://orcid.org/0000-0001-6773-8921)
- T. Sato (ORCID: https://orcid.org/0000-0002-4544-5463)
- K. Nakayama (ORCID: https://orcid.org/0000-0003-2462-2253)
- Kiyohisa Tanaka (ORCID: https://orcid.org/0000-0003-2779-5870)
- Takemi Kato (ORCID: https://orcid.org/0000-0003-4396-8292)
- R Settai
- Asuka Honma (ORCID: https://orcid.org/0009-0000-5972-209X)
- Koji Horiba (ORCID: https://orcid.org/0000-0002-1124-0451)
- Miho Kitamura (ORCID: https://orcid.org/0000-0002-9961-9019)
- Takayuki OSUMI (ORCID: https://orcid.org/0009-0004-1035-3608)
- A. F. Santander-Syro (ORCID: https://orcid.org/0000-0003-3966-2485)
- Tomonori Nakamura (ORCID: https://orcid.org/0000-0002-7702-8760)
- Yoshinori Okada (ORCID: https://orcid.org/0000-0001-9172-0844)
- Yoshichika Ōnuki
Institutions
- Centre National de la Recherche Scientifique (FR)
- High Energy Accelerator Research Organization (JP)
- Okinawa Institute of Science and Technology Graduate University (JP)
- The Graduate University for Advanced Studies, SOKENDAI (JP)
- Tohoku University (JP)
- Université Paris-Saclay (FR)
- Advanced Institute of Materials Science (JP)
- National Institutes for Quantum Science and Technology (JP)
- Institut des Sciences Moléculaires d'Orsay (FR)
- RIKEN Center for Emergent Matter Science (JP)
- Institute for Molecular Science (JP)
- Niigata University (JP)
Publication Details
- Journal
- Science Advances
- Published
- 2026-07-01
- DOI
- https://doi.org/10.1126/sciadv.aee3116
- Primary Topic
- Boron and Carbon Nanomaterials Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Australian Freshwater Sciences Society
- Japan Society for the Promotion of Science
- Core Research for Evolutional Science and Technology