Triangular monolayers: Indenene and beyond

ORAL

Abstract

Indenene is a triangular monolayer of indium on SiC(0001) [1,2] in which Kane-Mele-like quantum spin Hall physics emerges from the (px, py) orbitals rather than from the usual honeycomb sublattice degree of freedom. The quantum interference of the corresponding Bloch wave functions in the 2d-bulk can be directly probed by scanning tunneling microscopy, allowing for an experimental detection of non-trivial topology entirely based on the properties of the bulk wave functions rather than on edge quantum transport. Recently, the operability of indenene as a quantum spin Hall insulator in air has been achieved [3] and the role of orbital angular momentum has been unveiled by means of circular dichroism in angle-resolved photoemission spectroscopy [4]. Realizing similar monolayers with transition-metal elements, as proposed in [5], opens new directions for strongly correlated effects in topological bandstructures.

*Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) Germany’s Excellence Strategy: Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter ct.qmat (EXC 2147, Project ID 390858490)

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Publication: [1] M. Bauernfeind, J. Erhardt, P. Eck, et al. Design and realization of topological Dirac fermions on a triangular lattice. Nat Commun 12, 5396 (2021). https://doi.org/10.1038/s41467-021-25627-y

[2] P. Eck, C. Ortix, A. Consiglio, et al. Real-space obstruction in quantum spin Hall insulators. Phys. Rev. B 106, 195143 (2022) https://doi.org/10.1103/PhysRevB.106.195143

[3] C. Schmitt, J. Erhardt, P. Eck, et al. Achieving environmental stability in an atomically thin quantum spin Hall insulator via graphene intercalation. Nat Commun 15, 1486 (2024). https://doi.org/10.1038/s41467-024-45816-9

[4] J. Erhardt, C. Schmitt, P. Eck, et al. Bias-Free Access to Orbital Angular Momentum in Two-Dimensional Quantum Materials. Phys. Rev. Lett. 132, 196401 (2024). https://doi.org/10.1103/PhysRevLett.132.196401

[5] H. Menke, N. Enderlein, Y.-T. Tseng, et al. Engineering correlated Dirac fermions and flat bands on SiC with transition-metal adatom lattices https://doi.org/10.48550/arXiv.2410.17165

Presenters

  • Giorgio Sangiovanni

    • Julius-Maximilians University of Wuerzburg

Authors

  • Giorgio Sangiovanni

    • Julius-Maximilians University of Wuerzburg

  • Ralph Claessen

    • University of Wuerzburg

  • Simon Moser

    • University of Wuerzburg

  • Cedric Schmitt

    • University of Wuerzburg

  • Jonas Erhardt

    • University of Wuerzburg

  • Domenico Di Sante

    • University of Bologna

  • Gianni Profeta

    • University of l'Aquila

  • Mattia Iannetti

    • University of l'Aquila