Electronic structure of a doped Mott-Hubbard surface
The $\mathrm{Sn}/\mathrm{Si}(111)\ensuremath{-}(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})R{30}^{\ensuremath{\circ}}$ surface, a 2D Mott insulator, has long been predicted and then found experimentally to metallize and even turn superconducting upon boron doping. To clarify the structural, spectroscopic, and theoretical details of that evolution, here we present angle resolved photoemission spectra data supplementing morphology and scanning tunneling measurements. These combined experimental results are compared with predictions from a variety of electronic structure approaches, mostly density functional $\mathrm{DFT}+U$, but not neglecting Mott-Hubbard models, both ordered and disordered. These theoretical pictures address different spectroscopic aspects, including the 2D Fermi surface, the Hubbard bands, etc. While no single picture accounts for all observations at once, the emergent hypothesis compatible with all data is that metallization arises from sub-subsurface boron doping, alternatively to the main standard subsurface boron geometry that would leave the surface insulating. These results advance the indispensable frame for the further understanding of this fascinating system.
Authors
- Giovanni Di Santo (ORCID: https://orcid.org/0000-0001-9394-2563)
- Paolo Moras (ORCID: https://orcid.org/0000-0002-7771-8737)
- Cesare Tresca (ORCID: https://orcid.org/0000-0002-9587-0513)
- Tommaso Cea (ORCID: https://orcid.org/0000-0003-0577-4905)
- S. Modesti (ORCID: https://orcid.org/0000-0002-4563-0853)
- Polina M. Sheverdyaeva (ORCID: https://orcid.org/0000-0002-4231-1638)
- Erio Tosatti (ORCID: https://orcid.org/0000-0002-5219-7728)
- Marco Caputo (ORCID: https://orcid.org/0000-0001-7452-0998)
- G. Profeta (ORCID: https://orcid.org/0000-0002-0535-7573)
- Mattia Iannetti (ORCID: https://orcid.org/0009-0000-3683-0266)
- Fabio Chiapolino
Institutions
- The Abdus Salam International Centre for Theoretical Physics (ICTP) (IT)
- Scuola Internazionale Superiore di Studi Avanzati (IT)
- University of Trieste (IT)
- University of L'Aquila (IT)
- Elettra-Sincrotrone Trieste S.C.p.A. (IT)
- Superconducting and other Innovative Materials and Devices Institute (IT)
- Institute of Structure of Matter (IT)
- National Interuniversity Consortium of Materials Science and Technology (IT)
- Technical University of Munich (DE)
Publication Details
- Journal
- Physical review. B./Physical review. B
- Published
- 2025-08-28
- DOI
- https://doi.org/10.1103/ry9v-47x2
- Citations
- 1
- Primary Topic
- Algebraic structures and combinatorial models
- Type
- article
- Field-Weighted Citation Impact
- 4.09
Funders
- Università degli Studi di Perugia