Population dynamics of graphene driven by a few-cycle laser pulse

Abstract

We study the time evolution of the populations in a two-dimensional (2D) graphene system by employing a few-cycle laser pulse with a linear polarization. Specifically, we present a comparative numerical analysis of the population dynamics of graphene in three different model configurations. Our results show that the Rabi-like oscillations and intraband population inversion can be observed in the population spectrum, which originated from the periodicity of a few-cycle laser pulse and the intraband Coulomb scattering. Also, coherent population oscillations are produced across the Dirac point when the Rabi frequency of the laser field which is used to couple the interband transition is much larger than that couples the intraband transition, and vice versa. These investigations may be helpful to enhance the performance of graphene-based ultrafast electronic and optoelectronic devices, including light-emitting devices, touch screens, photodetectors, and ultrafast lasers.

Controllable population dynamics in Landau-quantized graphene

“…Before ending this section, let us briefly discuss the differences between our current and previous work 52 . (i) In our previous work, we used two opposite circularly polarized components of a few-cycle laser pulse with linear polarization to couple two different intraband Landau-level transitions.…”

Orbital angular momentum sensing of composite vortex light in a single-layer graphene system

“…The diagrams presented in figures 1(a) and (b) illustrates the arrangement of Landau levels in a single-layer graphene (SLG) system interacting with laser fields. This specific configuration has previously been employed to investigate notable optical nonlinearity, nonlinear frequency conversion, generation of entangled photons, and the formation of ultraslow solitons, as referenced in [15,26,[43][44][45]. By introducing an external magnetic field within the range of 0.01-10T, optical transitions between neighboring Landau levels (LLs) in graphene are expected to occur in the infrared to THz region.…”

“…Our investigation reveals that, owing to the radiation of THz signals, the probe absorption can be controlled across various regions, exhibiting a strong dependence on the OAM number of the vortex light. This dependence arises from distinct electrical characteristics and selection rules governing transitions between Landau levels near a Dirac point [26,43,44]. Consequently, a probe laser beam can generate a discernible nonlinear frequency even within a single monolayer of graphene.…”