Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 7: Correlated Electrons: Electronic Structure Calculations
TT 7.5: Vortrag
Montag, 17. März 2025, 16:00–16:15, H31
Engineering correlated Dirac fermions and flat bands on SiC with transition metal adatom lattices — •Niklas Enderlein1, Henri Menke1,2, Yi-Ting Tseng1, Michel Bockstedte3, Janina Maultzsch1, Giorgio Sangiovanni4, and Philipp Hansmann1 — 1Friedrich-Alexander-University Erlangen-Nürnberg — 2Max Planck Institute for Solid State Research, Stuttgart — 3Johannes Kepler University Linz — 4Julius-Maximilian-University of Würzburg
In our recent study [1] we propose three transition-metal adatom systems on 3C-SiC(111) surfaces as a versatile platform to realize massless Dirac fermions and flat bands with strong electronic correlations. Using density functional theory combined with the constrained random phase approximation and dynamical mean-field theory, we investigate the electronic properties of Ti, V, and Cr adatoms. The triangular surface lattices exhibit narrow bandwidths and effective two-band Hubbard models near the Fermi level, originating from partially filled, localized d-orbitals of the adatoms. Our study reveals a materials trend from a flat band Fermi liquid (Cr) via a paramagnetic Mott insulator with large local moments (V) to a Mott insulator on the verge to a heavy Dirac semimetal (Ti) showcasing the diverse nature of these strongly correlated systems. Specifically, the flat bands in the Cr and the well-defined Dirac cones in the strained metallic Ti lattice indicate high potential for realizing topological and correlated phases.
[1] H.Menke, N.Enderlein et al., arXiv:2410.17165.
Keywords: adatoms; Hubbard model; dynamical mean-field theory