Driving Quantum-Confined Massless Dirac Fermions: Floquet Graphene Antidot Lattices

Graphene antidot lattices are a convenient platform for exploring the properties of quantum-confined Dirac fermions in 2D. Changing the confinement strength by varying the geometric parameters (hole diameter and spacing) results in a widely tunable band gap. In similarity to pristine graphene [1], periodic driving with time-reversal symmetry breaking circularly polarized light has the potential to induce non-trivial topology in the quasienergy spectra. Based on the Floquet-Kubo formalism, the conductivity is calculated as the photon energy and electric field amplitude are varied across the topological transition, and constitutes a starting point for bridging between theory and future experiments. Furthermore, time-dependent density functional theory calculations are used to validate the simple Dirac Hamiltonian and Peierls substitution approaches. Floquet graphene antidot lattices may find application in solar cells, solid state spin qubit arrays, and parallel DNA sequencers.

[1] M. Schüler et al., Phys. Rev. X, 10, 041013 (2020)