Maxim Ryzhii

TL;DR: In this article, the dynamic ac conductivity of a nonequilibrium two-dimensional electron-hole system in optically pumped graphene was studied and it was shown that at sufficiently strong pumping the population inversion in graphene can lead to the negative net ac conductivities in the terahertz range of frequencies.

TL;DR: Graphene is a one-atom-thick planar sheet of a honeycomb carbon crystal and its gapless and linear energy spectra of electrons and holes lead to nontrivial features such as giant carrier mobility and broadband flat optical response as discussed by the authors.

TL;DR: In this paper, the effect of population inversion associated with the electron and hole injection in graphene p-i-n structures at the room and slightly lower temperatures was studied. And the dependences of the electron-hole and optical phonon effective temperatures on the applied voltage, the current-voltage characteristics, and the frequency-dependent dynamic conductivity were calculated.

TL;DR: In this paper, a multiple graphene layer (MGL) structure with a stack of GLs and a highly conducting bottom GL on SiC substrate pumped by optical radiation is considered as an active region of terahertz and far infrared lasers with external metal mirrors.

TL;DR: In this paper, a multiple-graphene-layer (MGL) structure with a stack of GLs and a highly conducting bottom GL on SiC substrate pumped by optical radiation is considered as an active region of terahertz (THz) and far infrared (FIR) lasers with external metal mirrors.