Dresden 2026 – scientific programme
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O: Fachverband Oberflächenphysik
O 74: Graphene: Electronic structure, excitations, etc. – Poster (joint session O/TT)
O 74.6: Poster
Wednesday, March 11, 2026, 18:00–20:00, P2
Vanishing Fermi velocity in Periodically Strained Graphene — •Leo-Malik Benneka1, Taher Rhouma2, Guy Trambly de Laissardière2, Clemens Winkelmann1, Mark Zelsmann3, and Vincent Renard1 — 1Université Grenoble Alpes, CEA-IRIG-PHELIQS, 38000 Grenoble, France — 2CNRS-LPTM, CY Cergy Paris Université, 95302 Cergy-Pontoise, France — 3CNRS-LTM, 38000 Grenoble, France
Intense research has been made in engineering flat bands in twisted bilayer graphene, leading to various correlated phases [1]. An alternative route to realizing similar flat bands involves a monolayer graphene strained by a periodic triangular superlattice induced by a corrugated substrate. The height modulation h and the superlattice periodicity L serve as tuning parameters for controlling band flattening and the Fermi velocity vF near the Dirac cones [2, 3]. Tight-binding calculations were performed by explicitly accounting for relative rotations between the graphene lattice and the superlattice, as would occur in an experimental device. These calculations not only reproduce the known decrease of the Fermi velocity with increasing h [4], but also reveal a renormalization of vF that depends on the specific ratio √aCC L/h and on the relative lattice orientation. Remarkably, this behavior is universal for any superlattice size L. These predictions may assist in the design of experimental devices aimed at engineering flat bands. [1] Cao et al., Nature, 556 (2018) 43-50 ; [2] Mao et al., Nature, 7820 (2020) 215-220 ; [3] Yuan et al., Phys. Rev. B, 24 (2024) 245408 ; [4] S. P. Milovanović et al., Phys. Rev. B, 24 (2020) 245427.
Keywords: Graphene; Fermi velocity; Flat bands; Localization; Strain