Ratchet effect in spatially modulated bilayer graphene: Signature of hydrodynamic transport

Abstract

We report on the observation of the ratchet effect -- generation of direct electric current in response to external terahertz (THz) radiation -- in bilayer graphene, where inversion symmetry is broken by an asymmetric dual-grating gate potential. As a central result, we demonstrate that at high temperature, $T=150\text{K}$, the ratchet current decreases at high frequencies as $\propto 1/{\omega }^2$, while at low temperature, $T=4.2\text{K}$, the frequency dependence becomes much stronger $\propto 1/{\omega }^6$. The developed theory shows that the frequency dependence of the ratchet current is very sensitive to the ratio of the electron-impurity and electron-electron scattering rates. The theory predicts that the dependence $1/{\omega }^6$ is realized in the hydrodynamic regime, when electron-electron scattering dominates, while $1/{\omega }^2$ is specific for the drift-diffusion approximation. Therefore, our experimental observation of a very strong frequency dependence reveals the emergence of the hydrodynamic regime.

21 pages, 12 figures

References in corpus (19)

• Gate-induced insulating state in bilayer graphene devices
• Artificial Brownian motors: Controlling transport on the nanoscale
• Graphene field effect transistors as room-temperature Terahertz detectors
• Hydrodynamics of electrons in graphene
• Imaging phonon-mediated hydrodynamic flow in WTe2
• Viscous electron fluids
• Control of electron-electron interaction in graphene by proximity screening
• Cyclotron resonance photoconductivity of a two-dimensional electron gas in HgTe quantum wells
• Hydrodynamic and ballistic transport over large length scales in GaAs/AlGaAs
• Viscosity of two-dimensional electrons
• Stokes flow around an obstacle in viscous two-dimensional electron liquid
• Thermal resistivity and hydrodynamics of the degenerate electron fluid in antimony
• Collision dominated, ballistic, and viscous regimes of terahertz plasmonic detection by graphene
• Manifestations of classical size effect and electronic viscosity in the magnetoresistance of narrow two-dimensional conductors: Theory and experiment
• Viscous magnetotransport and Gurzhi effect in bilayer electron system
• Terahertz electric field driven electric currents and ratchet effects in graphene
• Beatings of ratchet current magneto-oscillations in GaN-based grating gate structures: manifestation of spin-orbit band splitting
• Giant ratchet magneto-photocurrent in graphene lateral superlattices
• Rectification by hydrodynamic flow in an encapsulated graphene Tesla valve

Cited by in corpus (20)

• Fast and Sensitive Terahertz Detection in a Current-Driven Epitaxial-Graphene Asymmetric Dual-Grating-Gate FET Structure
• Non-linear Transport Phenomena and Current-induced Hydrodynamics in Ultra-high Mobility Two-dimensional Electron Gas
• Lateral plasmonic crystals: Tunability, dark modes, and weak-to-strong coupling transition
• Cyclotron- and magnetoplasmon resonances in bilayer graphene ratchets
• Plasmonic quantum nonlinear Hall effect in noncentrosymmetric 2D materials
• Temperature Dependent Zero-Field Splittings in Graphene
• Nonlinear density waves on graphene electron fluids
• Nonlinear intensity dependence of ratchet currents induced by terahertz laser radiation in bilayer graphene with asymmetric periodic grating gates
• Spin and Valley Hall effects induced by asymmetric interparticle scattering
• Terahertz ratchet in graphene 2D metamaterial formed by a patterned gate with an antidot arrayd
• Terahertz spin ratchet effect in magnetic metamaterials
• Observability of cyclotron resonance in the hydrodynamic regime of bilayer graphene
• Circular THz ratchets in a 2D-modulated Dirac system
• Photon drag at the junction between metal and 2d semiconductor
• Terahertz and gigahertz magneto-ratchets in graphene-based 2D metamaterials
• Spin-dependent photovoltage in graphene/MoS2-based field-effect transistors
• Exact theory of edge diffraction and launching of transverse electric plasmons at two-dimensional junctions
• Photogalvanic effect in hydrodynamic flows of nonreciprocal electron liquids
• Strong photoresponse of edge two-dimensional electrons in a magnetic field
• Skew scattering and ratchet effect in photonic graphene