Hundredth anniversary of the birth of A. F. Ioffe: Academician A. F. Ioffe and Soviet science

Aleksandrov, A P

doi:10.1070/pu1980v023n09abeh005853

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Stationary distributions of electrons in strong laser fields can be very peculiar compared to the electron distribution [6] in conventional (gapped) semiconductors. In the latter case with a large bandgap one can readily reach a quasi-equilibrium Fermi-Dirac distribution of electrons pumped into the conduction band and holes in the valence band, and an insulating state due to the isotropic optical gap (the so-called "optical" insulator [8]). However, such degenerate distributions seem to be improbable in graphene, since photoelectrons can recombine with photoholes with about the same rate as their energy relaxation rate.…”

mentioning

confidence: 99%

Massless Dirac fermions in a laser field as a counterpart of graphene superlattices

Savel’ev

Alexandrov

2011

Phys. Rev. B

View full text Add to dashboard Cite

We establish an analogy between spectra of Dirac fermions in laser fields and an electron spectrum of graphene superlattices formed by static 1D periodic potentials. The general relations between a laser-controlled spectrum where electron momentum depends on the quasi-energy and a superlattice mini-band spectrum in graphene are derived. As an example we consider two spectra generated by a pulsed laser and by a step-like electrostatic potential. We also calculate the graphene excitation spectrum in continuous strong laser fields in the resonance approximation for linear and circular polarizations and show that circular polarized laser fields cannot be reduced to any graphene electrostatic superlattice. Some physical phenomena related to the peculiar graphene energy spectrum in the strong electromagnetic field are discussed.PACS numbers: 68.43.Mn A huge surge of interest to graphene (see e.g., [1,2]) as the only two dimensional material known so far stimulates studies of one dimensional and two dimensional graphene superlattices (see e.g., [3]). In analogy to usual semiconducting superlattices, it is commonly accepted that such graphene superlattices should allow to manipulate the electron spectra and transport properties in graphene-based electronics. However, there is still a limited number of studies on how time-dependent electric field (for instance laser field) can affect both the electron spectrum and transport in graphene. Most studies done so far are focused on a perturbative response of graphene in weak (probe) electromagnetic time-dependent fields [4]. A growing experimental demand [5] on the data analysis of optical properties and electron transport in graphene in strong laser fields is the main motivation of this work.Another motivation is to study temporal-spatial symmetry for massless Dirac fermions in periodic time or spatial electric fields. Spatial periodic potentials U (x) with its period much larger than the interatomic distance transforms the Dirac cone energy spectrum ε(p x , p y ) with electron momentum p = (p x , p y ) into a set of minibands ε n (p x , p y ) [3] where the quasi-momentum p x =hk x or the electron wave vector k x takes values within the first superlattice Brillouin zone −π/L < k x < π/L, while the y-momentum p y =hk y is unbound. Here L is the spatial period of an electric field E x (x) and an integer n numerates different subbands (which are usually separated by gaps). In contrast to the above picture, applying time periodic electric fields E x (t) should change the spectrum of electrons in accordance with the Floquet theory stating that the electron energy should become a quasi-energy ε bounded within its Brillouin zone −π/T < E < π/T with E = ε/h and T is the temporal period of homogeneous electric field E x (t) applied along the x-axis. Therefore, the electron spectrum in time-periodic laser fields could be written in the form k x = k x (ε, k y ). This analogy raises several questions, including the possibility of gaps in the spectrum for either momentum k x or quasi-...

show abstract

mentioning

confidence: 99%

Massless Dirac fermions in a laser field as a counterpart of graphene superlattices

Savel’ev

Alexandrov

2011

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…Although several authors have analysed the plasma capacitor problem (for example, Hall 1963;Balmain 1966;Weissglas 1962;Aleksandrov 1965a, b) their treatments were either for the case where a fluid model was used to describe the plasma or, for those treatments using a kinetic plasma model, restricted to the case where the specular reflexion boundary condition was used for the distribution function at each of the plasma interfaces. It is our object here to present a complete formal solution to the problem for each of the three boundary conditions in common use: the specular reflexion, the absorption and the diffuse scattering boundary conditions.…”

Section: Introductionmentioning

confidence: 99%

The plasma capacitor problem

Elgin

1981

J. Plasma Phys.

View full text Add to dashboard Cite

The problem of the penetration of a longitudinal electric field into a bounded plasma layer is considered. The method of solution is based on the representation of the disturbance in the plasma layer as that generated by an appropriate charge source in the complementary regions into which, for the purpose of the representation, the plasma is conceived to extend. The problem is solved for each of the three boundary conditions in common use: these are the specular refiexion, the absorption and the diffuse scattering boundary conditions.

show abstract

Hundredth anniversary of the birth of A. F. Ioffe: Academician A. F. Ioffe and Soviet science

Cited by 2 publications

References 0 publications

Massless Dirac fermions in a laser field as a counterpart of graphene superlattices

Massless Dirac fermions in a laser field as a counterpart of graphene superlattices

The plasma capacitor problem

Contact Info

Product

Resources

About