Nonlinear intensity dependence of photogalvanics and photoconductance induced by terahertz laser radiation in twisted bilayer graphene close to magic angle

Abstract

We report on the observation of the nonlinear intensity dependence of the bulk photogalvanic current and photoconductivity in the twisted graphene with small twist angles close to the second magical angle. We show that terahertz radiation results in the photoresponses, which is caused by indirect optical transitions (free carrier absorption), direct interband transitions and optical transitions between Moiré subbands. The relative contribution of these absorption channels depends on the Fermi level position with respect to the multiple Moiré subbands of the twisted graphene. The interplay of these absorption channels results in oscillations of the photoresponses with variation of the gate voltage. We show that the photoresponse saturates at high intensities. For different absorption channels it has different intensity dependencies and saturation intensities. The latter depends non-monotonically on the Fermi level position, which is controlled by the gate voltage.

arXiv comment10 pages , 7 figures

References in corpus (49)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Moire bands in twisted double-layer graphene
• Tuning superconductivity in twisted bilayer graphene
• Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
• Superconductors, Orbital Magnets, and Correlated States in Magic Angle Bilayer Graphene
• Graphene bilayer with a twist: electronic structure
• Intrinsic quantized anomalous Hall effect in a moiré heterostructure
• Observation of Van Hove singularities in twisted graphene layers
• Magic Angle Spectroscopy
• Flat Bands in Slightly Twisted Bilayer Graphene
• Atomic and electronic reconstruction at van der Waals interface in twisted bilayer graphene
• Imaging Electronic Correlations in Twisted Bilayer Graphene near the Magic Angle
• Charge-Order and Broken Rotational Symmetry in Magic Angle Twisted Bilayer Graphene
• Single Layer Behavior and Its Breakdown in Twisted Graphene Layers
• Spin-polarized Correlated Insulator and Superconductor in Twisted Double Bilayer Graphene
• Twistable electronics with dynamically rotatable heterostructures
• Tunable Moiré Bands and Strong Correlations in Small-Twist-Angle Bilayer Graphene
• Origin of Mott insulating behavior and superconductivity in twisted bilayer graphene
• Correlated states in twisted double bilayer graphene
• Maximally-localized Wannier orbitals and the extended Hubbard model for the twisted bilayer graphene
• Strange metal in magic-angle graphene with near Planckian dissipation
• Untying the insulating and superconducting orders in magic-angle graphene
• Twist-controlled resonant tunnelling in graphene-boron nitride-graphene heterostructures
• Theory of phonon-mediated superconductivity in twisted bilayer graphene
• Commensuration and Interlayer Coherence in Twisted Bilayer Graphene
• Electric field tunable unconventional superconductivity in alternating twist magic-angle trilayer graphene
• Electronic properties of graphene-based bilayer systems
• Topological Superconductivity in Twisted Multilayer Graphene
• Nematicity and Competing Orders in Superconducting Magic-Angle Graphene
• Chern Insulators and Topological Flat-bands in Magic-angle Twisted Bilayer Graphene
• Symmetry broken Chern insulators and magic series of Rashba-like Landau level crossings in magic angle bilayer graphene
• Twisted bilayer graphene I. Matrix elements, approximations, perturbation theory and a $k\cdot p$ 2-Band model
• Photon Drag Effect in (Bi${}_{1-x}$Sb${}_x$)${}_2$Te${}_3$ Three Dimensional Topological Insulators
• Magneto-Gyrotropic Photogalvanic Effects in Semiconductor Quantum Wells
• Multiple Flat Bands and Topological Hofstadter Butterfly in Twisted Bilayer Graphene Close to the Second Magic Angle
• Spin photocurrents and circular photon drag effect in (110)-grown quantum well structures
• Photogalvanic probing of helical edge channels in 2D HgTe topological insulators
• Spin sensitive bleaching and monopolar spin orientation in quantum wells
• Nano-imaging photoresponse in a moiré unit cell
• Graphene-based light sensing: fabrication, characterisation, physical properties and performance
• Hyperbolic enhancement of photocurrent patterns in minimally twisted bilayer graphene
• Nano-photocurrent mapping of local electronic structure in twisted bilayer graphene
• Terahertz photogalvanics in twisted bilayer graphene close to the second magic angle
• Highly superlinear photogalvanic effects in (Bi${}_{0.3}$Sb${}_{0.7}$)${}_2$(Te${}_{0.1}$Se${}_{0.9}$)${}_3$: Probing 3D topological insulator surface states at room temperature
• Nonlinear intensity dependence of terahertz edge photocurrents in graphene
• Edge photocurrent in bilayer graphene due to inter-Landau-level transitions
• High frequency impact ionization and nonlinearity of photocurrent induced by intense terahertz radiation in HgTe-based quantum well structures
• Nonlinear Absorption and Photocurrent in Weyl Semimetals

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• Nonlinear intensity dependence of ratchet currents induced by terahertz laser radiation in bilayer graphene with asymmetric periodic grating gates
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• Ferromagnetism vs. Antiferromagnetism in Narrow-Band Systems: Competition Between Quantum Geometry and Band Dispersion