Dirac fermion time-Floquet crystal: manipulating Dirac points

Abstract

We demonstrate how to control the spectra and current flow of Dirac electrons in both a graphene sheet and a topological insulator by applying either two linearly polarized laser fields with frequencies $\omega$ and $2\omega$ or a monochromatic (one-frequency) laser field together with a spatially periodic static potential(graphene/TI superlattice). Using the Floquet theory and the resonance approximation, we show that a Dirac point in the electron spectrum can be split into several Dirac points whose relative location in momentum space can be efficiently manipulated by changing the characteristics of the laser fields. In addition, the laser-field controlled Dirac fermion band structure -- Dirac fermion time-Floquet crystal -- allows the manipulation of the electron currents in graphene and topological insulators. Furthermore, the generation of dc currents of desirable intensity in a chosen direction occurs when applying the bi-harmonic laser field which can provide a straightforward experimental test of the predicted phenomena.

9 pages, 7 figures, version that will appear in Phys. Rev. B

References in corpus (13)

• The electronic properties of graphene
• Chiral tunneling and the Klein paradox in graphene
• Unconventional Integer Quantum Hall effect in graphene
• Observation of Floquet-Bloch states on the surface of a topological insulator
• Quantum interference and Klein tunneling in graphene heterojunctions
• Evidence of Klein tunneling in graphene p-n junctions
• Anisotropic behaviors of massless Dirac fermions in graphene under periodic potential
• New Generation of Massless Dirac Fermions in Graphene under External Periodic Potentials
• Photoinduced transition between conventional and topological insulators in two-dimensional electronic systems
• Tuning laser-induced bandgaps in graphene
• Radiation effects on the electronic structure of bilayer graphene
• Electromagnetic field induced suppression of transport through $n$-$p$ junctions in graphene
• Nonlinear magnetization of graphene

Cited by in corpus (8)

• Irradiated graphene as a tunable Floquet topological insulator
• Aspects of Floquet Bands and Topological Phase Transitions in a Continuously Driven Superlattice
• Topological Floquet engineering using two frequencies in two dimensions
• Dynamical properties of a driven dissipative dimerized $S=1/2$ chain
• Ratchet effect in graphene with trigonal clusters
• Observation of Floquet-induced gap in graphene
• Coherent destruction of tunneling in graphene irradiated by elliptically polarized lasers
• THz Photodetector using sideband-modulated transport through surface states of a 3D Topological Insulator