Topological Floquet Engineering of Twisted Bilayer Graphene
ORAL
Abstract
In twisted bilayer graphene (TBG), the choice of the twist angle allows for tailored engineering of the low energy absorption spectrum. This tunability makes TBG a perfect playground for Floquet engineering. Motivated by the measurement of ultrafast light-induced Hall currents in monolayer graphene [1], we investigate the topological properties of twisted bilayer graphene for an intermediate twisting angle in and out of equilibrium on the basis a full Moiré-unit-cell tight-binding model [2]. By breaking time-reversal symmetry with a circularly polarized light field, we induce a transition to a topologically non-trivial Floquet band structure with a Berry curvature analogous to a Chern insulator, which can be controlled via inversion-symmetry-breaking back-gate potentials. Additionally, I will discuss preliminary results of my ongoing work on light-matter couplings in magic-angle twisted bilayer graphene (MATBG).
[1] J. M. McIver et al., Nature Physics 16, 38-41 (2020)
[2] G. E. Topp et al. PRR 1, 023031 (2019)
[1] J. M. McIver et al., Nature Physics 16, 38-41 (2020)
[2] G. E. Topp et al. PRR 1, 023031 (2019)
*G.E.T. and M.A.S. acknowledge financial support by the DFG through the Emmy Noether program (No. SE 2558/2-1). This work was supported by the European Research Council (No. ERC-2015-AdG694097)
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Presenters
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Gabriel Topp
- Aalto University