相关论文: The optical selection rules of a graphene quantum …
We demonstrated theoretically that the renormalization of the electron energy spectrum near the Dirac point of graphene by a strong high-frequency electromagnetic field (dressing field) drastically depends on polarization of the field.…
We study electron scattering in graphene quantum dots (GQDs) under the combined influence of a magnetic field, an energy gap, and circularly polarized laser irradiation. Using the Floquet approach and the Dirac equation, we derive the…
We present a theory of electronic properties of gated triangular graphene quantum dots with zigzag edges as a function of size and carrier density. We focus on electronic correlations, spin and geometrical effects using a combination of…
The inter-band optical absorption in graphene characterized by its fine-structure constant has a universal value of 2.3\% independent of the material parameters. However, for several graphene-based photonic applications, enhanced optical…
On the basis of the Kubo formula we evaluated the optical conductivity of a graphene sheet. The full behavior of frequency as well as temperature dependence of the optical conductivity is presented. We show that the anisotropy of…
We analyze the bound-state spectra of mass-profile quantum dots in graphene, a system at current experimental reach. Homogeneous perpendicular magnetic fields are also considered which result in breaking the valley degeneracy. The spectra…
We show how coupling to an Einstein phonon $\omega_E$ affects the absorption peaks seen in the optical conductivity of graphene under a magnetic field $B$. The energies and widths of the various lines are shifted, and additional peaks arise…
We study optical spectra of finite electronic quantum systems at frequencies smaller than the plasma frequency using a quasi-classical approach. This approach includes collective effects and enables us to analyze how the nature of the…
The structure stability and electronic properties of edge carboxylated hexagonal and triangular graphene quantum dots are investigated by using density functional theory. The calculated binding energies show that the hexagonal clusters with…
We theoretically analyze the scattering process of an electron on a graphene quantum dot (GQD) exposed to an external light irradiation. We prove that for suitable choices of the light polarization state, there emerge scattering resonances,…
Strongly-coupled quantum dot molecules (QDMs) are widely deployed in the design of a variety of optoelectronic, photovoltaic, and quantum information devices. An efficient and optimized performance of these devices demands engineering of…
We investigate high resolution laser absorption spectroscopy of a single InGaAs/GaAs self-assembled quantum dot embedded in a field-effect structure. We show experimentally that the interband optical absorption to the lower Zeeman branch of…
A graphene quantum dot under intense ac field and static low magnetic field is investigated. From a tight-binding perspective, applying a Fourier-Floquet transformation and renormalization process, we observe that graphene -intrinsically…
Graphene monolayer is a material with zero band gap, because of which its applications in optoelectronics are limited. The question arises, can we modify the optoelectronic properties of graphene by doping it with other atoms? Synthesis of…
The optical absorption properties of graphene wrapped dielectric particles have been investigated by using Mie scattering theory and exact multi-scattering method. It is shown that subwavelength strong absorption in infrared spectra can…
We investigate theoretically the magnetic levels and optical properties of zigzag- and armchair-edged hexagonal graphene quantum dots (GQDs) utilizing the tight-binding method. A new bound edge state at zero energy appears for the zigzag…
In this work we argue that it is important to make a proper choice of the unit cell within tight-binding theory if one aims to compute the optical matrix elements. By considering zigzag graphene nanoribbons, we demonstrate that the band…
The energy levels and optical transitions of tetrahedral core/shell InP/ZnSe quantum dots (QDs) are investigated by means of multi-band k$\cdot$p theory. Despite the $\overline{T}_d$ symmetry relaxing spherical selection rules, the…
We investigate a singly-charged quantum dot under a strong optical driving field by probing the system with a weak optical field. When the driving field is detuned from the trion transition, the probe absorption spectrum is shifted from the…
We have theoretically investigated the electronic and magnetic properties of graphene whose zigzag edges are oxidized. The alteration of these properties by adsorption of $\mathrm{H_{2}O}$ and $\mathrm{NH_3}$ molecules have been considered.…