Electronic Transport and Photoemission Fingerprints of Floquet Graphene Antidot Lattices*

The Floquet graphene antidot lattice is a periodically hole-patterned graphene sheet driven periodically by electromagnetic radiation [1]. Notably, the equilibrium semiconducting state in such a system can be steered through Floquet Dirac, selectively dynamically localized, or Floquet semi-Dirac electronic phases by irradiation with circularly polarized near-IR radiation of suitable intensity. Experimentally, light-driven materials are probed by electronic transport measurements [2] and time- and angle- resolved photoemission spectroscopy (TR-ARPES) [3]. Thus, in order to connect the predicted Floquet electronic phases to experiment, we set out to model these measurement schemes. For electronic transport, the components of the frequency-dependent electrical conductivity tensor were computed at the level of linear response by means of the Floquet-Kubo formula [4]. Additionally, we utilized subcycle resolved photocurrent theory for TR-ARPES [5]. For the phases under consideration, the combination of the computed conductivity frequency sweeps and photocurrent spectra provides an unambiguous mapping between the quasienergy band structures predicted within the Floquet formalism and experimentally accessible quantities.

 

[1] Floquet Graphene Antidot Lattices, Cupo et al., Phys. Rev. B, 2021

[2] Light-Induced Anomalous Hall Effect in Graphene, McIver et al., Nat. Phys., 2020

[3] Selective Scattering Between Floquet–Bloch and Volkov States in a Topological Insulator, Mahmood et al., Nat. Phys., 2016

[4] Floquet-Drude Conductivity, Wackerl et al., Phys. Rev. B, 2020

[5] Theory of Subcycle Time-Resolved Photoemission: Application to Terahertz Photodressing in Graphene, Schüler and Sentef, arXiv:2103.15900v2, 2021