Optical Response and Ground State of Graphene

Abstract

The optical response and the ground state of graphene and graphene-like systems are determined self-consistently. Deriving equations of motion for the basic variables, graphene Bloch equations are introduced and combined with a variational Ansatz for the ground state. Within the Hartree--Fock approximation, this approach reproduces the gap equation for the ground state. The results show that the Coulomb interaction drastically influences the optical response of graphene and introduces an extremely sensitive dependency on the dielectric environment via screening. Regarding the effective fine-structure constant as control parameter, a transition from a semimetal to an excitonic insulator is predicted as soon as the effective graphene fine-structure constant exceeds a value of roughly 0.5. Above this critical value, the computed optical spectra exhibit a pseudogap and several bright $p$-like excitonic resonances.

13 pages, 13 figures

References in corpus (14)

• Electric Field Effect in Atomically Thin Carbon Films
• Dielectric function, screening, and plasmons in 2D graphene
• Excitonic Effects on the Optical Response of Graphene and Bilayer Graphene
• Interactions and phase transitions on graphene's honeycomb lattice
• Tuning the effective fine structure constant in graphene: opposing effects of dielectric screening on short- and long-range potential scattering
• Quantum critical transport in clean graphene
• Is graphene in vacuum an insulator?
• The Coulomb impurity problem in graphene
• Atomic Collapse and Quasi-Rydberg States in Graphene
• Coulomb interaction, ripples, and the minimal conductivity of graphene
• Lattice field theory simulations of graphene
• Supercritical Coulomb center and excitonic instability in graphene
• Variational approach to the excitonic phase transition in graphene
• Excitons in Graphene and the Influence of the Dielectric Environment

Cited by in corpus (29)

• Diabatic Mechanisms of Higher-Order Harmonic Generation in Solid-State Materials under High-Intensity Electric Fields
• High-Harmonic Generation from Monolayer and Bilayer Graphene
• Spin-Triplet Excitonic Insulator: The Case of Graphone
• Microscopic mechanism for transient population inversion and optical gain in graphene
• Influence of the effective layer thickness on the groundstate and excitonic properties of transition-metal dichalcogenide systems
• Bielectron vortices in two-dimensional Dirac semimetals
• Impact of electron-electron Coulomb interaction on the high harmonic generation process in graphene
• Nonlinear quantum optical properties of graphene: the role of chirality and symmetry
• Theory of optically induced Förster Coupling in van der Waals coupled Heterostuctures
• On the Optical Properties of Excitons in Buckled 2D Materials in an External Electric Field
• Excitonic Gap Formation in Pumped Dirac Materials
• Ultrafast band-gap renormalization and build-up of optical gain in monolayer MoTe${}_2$
• Magneto-optical and optical probes of gapped ground states of bilayer graphene
• Nonlinear optical response of doped mono- and bilayer graphene: length gauge tight-binding model
• Optically bright $p$-excitons indicating strong Coulomb coupling in transition-metal dichalcogenides
• Moving zero-gap Wannier-Mott excitons in graphene
• Microscopic theory of ultrafast dynamics of carriers photoexcited by THz and near-infrared linearly-polarized laser pulses in graphene
• Can freestanding Xene monolayers behave as excitonic insulators?
• Shear-Strain Controlled High-Harmonic Generation in Graphene
• Screening and gap generation in bilayer graphene
• Excitonic Instabilities and Insulating States in Bilayer Graphene
• Atomic real-space perspective of light-field-driven currents in graphene
• Sub-band picture of high-harmonic generation in solids
• Transport through vertical graphene contacts under intense laser fields
• Third harmonic generation of undoped graphene in Hartree-Fock approximation
• Plunging in the Dirac sea using graphene quantum dots
• Transport properties of vertical heterostructures under light irradiation
• Particle-hole pair states of layered materials
• Long-lived Nonlinear Oscillatory States in Interacting Relativistic Bose-Einstein Condensates