Dynamic Hall Effect Driven by Circularly Polarized Light in a Graphene Layer

Topological insulators represent unique phases of matter with insulating bulk and conducting edge or surface states, immune to small perturbations such as backscattering due to disorder. This stems from their peculiar band structure, which provides topological protections. While conventional tools (pressure, doping etc.) to modify the band structure are available, time periodic perturbations can provide tunability by adding time as an extra dimension enhanced to the problem. In this short review, we outline the recent research on topological insulators in non equilibrium situations. Firstly, we introduce briefly the Floquet formalism that allows to describe steady states of the electronic system with an effective time-independent Hamiltonian. Secondly, we summarize recent theoretical work on how light irradiation drives semi-metallic graphene or a trivial semiconducting system into a topological phase. Finally, we show how photons can be used to probe topological edge or surface states.Comment: 7 pages, 4 figures, comments are welcom

show abstract

“…Our predictions could in principle be tested by experiments similar to those in graphene [41] and HgTe/CdTe quantum wells [42].…”

Section: Probing Helical Edge States By Lightmentioning

confidence: 99%

Floquet topological insulators

Cayssol

Dóra

Simón

et al. 2013

Physica Rapid Research Ltrs

450

354

View full text Add to dashboard Cite

show abstract

“…We note in passing that, when the external magnetic field is absent, a dynamic Hall effect can still be induced by using circularly polarized light impinging on graphene at a finite angle with the normal to the graphene surface. 23 In the theoretical side, the magneto-optical transport properties of graphene have been investigated with the Green's function method 8,10 , and by means of numerical implementations of the Kubo formula, us-ing exact diagonalization 19 and Chebyshev polynomial expansions. 24 These approaches come with pros and cons: numerical studies allow to explore general scenarios, whereas Green's functions allows to obtain analytic results, but many times at the expense of a lengthy calculations.…”

Section: Introductionmentioning

confidence: 99%

Faraday effect in graphene enclosed in an optical cavity and the equation of motion method for the study of magneto-optical transport in solids

et al. 2011

View full text Add to dashboard Cite

We show that by enclosing graphene in an optical cavity, giant Faraday rotations in the infrared regime are generated and measurable Faraday rotation angles in the visible range become possible. Explicit expressions for the Hall steps of the Faraday rotation angle are given for relevant regimes. In the context of this problem we develop an equation of motion (EOM) method for the calculation of the magneto-optical properties of metals and semiconductors. It is shown that properly regularized EOM solutions are fully equivalent to the Kubo formula.

show abstract

“…To generate ratchet currents in unbiased samples we used alternating electric fields E(t) of a pulsed terahertz NH 3 laser, optically pumped by a transversely excited atmosphere pressure (TEA) CO 2 laser [21,22]. The laser operated at frequencies f = 3.32 THz (wavelength λ = 90.5 µm), 2.03 THz (λ = 148 µm) or 1.07 THz (λ = 280 µm).…”

Section: Samples and Techniquementioning

confidence: 99%

Magnetic quantum ratchet effect in Si-MOSFETs

Ганичев¹,

Tarasenko²,

Karch³

et al. 2014

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

We report on the observation of magnetic quantum ratchet effect in metal-oxide-semiconductor field-effect-transistors on silicon surface (Si-MOSFETs). We show that the excitation of an unbiased transistor by ac electric field of terahertz radiation at normal incidence leads to a direct electric current between the source and drain contacts if the transistor is subjected to an in-plane magnetic field. The current rises linearly with the magnetic field strength and quadratically with the ac electric field amplitude. It depends on the polarization state of the ac field and can be induced by both linearly and circularly polarized radiation. We present the quasi-classical and quantum theories of the observed effect and show that the current originates from the Lorentz force acting upon carriers in asymmetric inversion channels of the transistors.

show abstract

Dynamic Hall Effect Driven by Circularly Polarized Light in a Graphene Layer

Cited by 171 publications

References 12 publications

Floquet topological insulators

Floquet topological insulators

Faraday effect in graphene enclosed in an optical cavity and the equation of motion method for the study of magneto-optical transport in solids

Magnetic quantum ratchet effect in Si-MOSFETs

Contact Info

Product

Resources

About