Observation of Floquet-induced gap in graphene
arXiv:2603.28725 · doi:10.1038/s41563-026-02549-y
Abstract
Floquet engineering provides a powerful pathway for creating non-equilibrium phases of matter with tailored electronic structures and properties through time-periodic driving. As the original theoretical prototype, graphene established the framework in which the Floquet topological insulator with light-induced anomalous Hall effect was proposed. However, the defining spectroscopic signature of Floquet engineering in graphene--light-induced hybridization (avoided-crossing) gap at Floquet band crossings, has remained experimentally elusive. Here, we report direct observation of Floquet-induced hybridization gap in monolayer graphene under resonant driving by a strong light field. Time- and angle-resolved photoemission spectroscopy reveals gap opening at Floquet band crossings, accompanied by coherent Floquet sidebands. The gap exhibits pronounced momentum anisotropy, featuring two Dirac nodes protected by the spatiotemporal symmetry and tunable by light polarization. These results provide long-sought experimental demonstration of Floquet band engineering in graphene, opening up opportunities for light-field engineered quantum phases in graphene and related materials.
References in corpus (42)
- The electronic properties of graphene
- Topological Photonics
- Photonic Floquet Topological Insulators
- Substrate-induced band gap opening in epitaxial graphene
- Experimental realisation of the topological Haldane model
- Floquet Topological Insulator in Semiconductor Quantum Wells
- Photovoltaic Hall effect in graphene
- Observation of Floquet-Bloch states on the surface of a topological insulator
- Atomic quantum gases in periodically driven optical lattices
- Transport properties of non-equilibrium systems under the application of light: Photo-induced quantum Hall insulators without Landau levels
- Floquet Engineering of Quantum Materials
- Light-induced anomalous Hall effect in graphene
- Nonthermal pathways to ultrafast control in quantum materials
- Snapshots of non-equilibrium Dirac carrier distributions in graphene
- Selective scattering between Floquet-Bloch and Volkov states in a topological insulator
- Origins of anomalous electronic structures of epitaxial graphene on silicon carbide
- Floquet Spectrum and Transport Through an Irradiated Graphene Ribbon
- Irradiated graphene as a tunable Floquet topological insulator
- Light-induced emergent phenomena in 2D materials and topological materials
- Theory of pump-probe photoemission in graphene: Ultrafast tuning of Floquet bands and local pseudospin textures
- Tuning laser-induced bandgaps in graphene
- Pseudospin-selective Floquet band engineering in black phosphorus
- Merging of Dirac points and Floquet topological transitions in AC driven graphene
- Dissipative Floquet Topological Systems
- Microscopic theory for the light-induced anomalous Hall effect in graphene
- Optical response of graphene under intense terahertz fields
- Effect of radiation on transport in graphene
- Tracking primary thermalization events in graphene with photoemission at extreme timescales
- Direct determination of mode-projected electron-phonon coupling in the time-domain
- On the survival of Floquet-Bloch states in the presence of scattering
- Driven Electronic States at the Surface of a Topological Insulator
- Topological Floquet Engineering of Twisted Bilayer Graphene
- Massless Dirac fermions in a laser field as a counterpart of graphene superlattices
- Steady Floquet-Andreev States Probed by Tunnelling Spectroscopy
- Observation of Floquet states in graphene
- Direct observation of Floquet-Bloch states in monolayer graphene
- Steady state of interacting Floquet insulators
- Self-energy dynamics and mode-specific phonon threshold effect in a Kekulé-ordered graphene
- Dirac fermion time-Floquet crystal: manipulating Dirac points
- Engineering Dirac states in graphene: Coexisting type-I and type-II Floquet-Dirac fermions
- Detecting light-induced Floquet band gaps of graphene via trARPES
- High harmonic generation light source with polarization selectivity and sub-100-m beam size for time- and angle-resolved photoemission spectroscopy