Gerard Czajkowski

Electro-optical properties of Rydberg excitons

We show how to compute the electrooptical functions (absorption, reflection, and transmission) when Rydberg Excitons appear, including the effect of the coherence between the electron-hole pair and the electromagnetic field. With the use of Real Density Matrix Approach numerical calculations applied for Cu

Polaritons in anisotropic semiconductors

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Optical Properties of Rydberg Excitons and Polaritons

0 crystal are performed. We also examine in detail and explain the dependence of the resonance displacement on the state number and applied electric field strength. We report a good agreement with recently published experimental data.

Excitonic spectra of wide parabolic quantum wells

We show how to compute the optical properties (reflection and absorption) of anisotropic semiconductors in the exciton energy region, taking into account polariton and electron-hole coherence effects. The method is applied to a GaAs/Ga1−xAlxAs superlattice, and the modifications in the optical properties with respect to GaAs are related to the anisotropy.

Electrooptical functions and ellipsometric parameters of excitons in cylindrical quantum dots

We show how to compute the optical functions when Rydberg Excitons appear, including the effect of the coherence between the electron-hole pair and the electromagnetic field. We use the Real Density Matrix Approach (RDMA), which, combined with Greens function method, enables one to derive analytical expressions for the optical functions. Choosing the susceptibility, we performed numerical calculations appropriate to a Cu

Electro-optical properties of Cu

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0 crystal. The effect of the coherence is displayed in the line shape. We also examine in details and explain the dependence of the oscillator strength and the resonance placement on the state number. We report a good agreement with recently published experimental data.

O in the regime of Franz-Keldysh oscillations

The optical properties of wide quantum wells are considered, taking into account the screened electron-hole interaction potential and parabolic confinement potentials, different for the electrons and for the holes. The role of the interaction potential which mixes the energy states according to different quantum numbers is stressed. The results obtained by our method are in agreement with the observed spectra and give the possibility to the assessment of the resonances.

Polaritonic effects in superlattices.

We show how to compute the optical functions (the complex electrosusceptibility tensor, dielectric function, electroreflection spectra and ellipsometric parameters) for semiconductor quantum dots (QD) exposed to a uniform electric field in the growth direction, including the excitonic effects. The method uses the microscopic calculation of the QD excitonic wave functions and energy levels, and the macroscopic real density matrix approach (RDMA) to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation. In the microscopic calculations we solve the 6-dimensional two-particles Schrodinger equation by transforming it into an infinite set of coupled second order 2-dimensional differential equations with the appropriate boundary conditions. These differential equations are solved numerically giving the eigenfunctions and the energy eigenvalues. Then we used the RDMA and computed the frequency- and electric field strength dependent complex excitonic susceptibility tensor. The above approach enables us to determine the relative oscillator strength connected with excitonic resonances and to find the averaged susceptibilities for light- and heavy-holes excitons. Having the frequency dependent complex susceptibility tensor, we calculate the electrooptical functions for a QD. Numerical calculations have been performed for a InGaAs QD with a constant electric field applied in the growth direction. The optical Stokes parameters and ellipsometric parameters ψ and Δ as functions of the frequency and the angle of incidence are also determined. A good agreement with experiment is obtained.

Electro-optical properties of semiconductor superlattices in the regime of Franz-Keldysh oscillations

We present the analytical method enables one to compute the optical functions i.e., reflectivity, transmission and absorption including the excitonic effects for a semiconductor crystal exposed to a uniform electric field for energy region above the gap, for external field suitable to appearance of Franz-Keldysh (FK) oscillations. Our approach intrinsically takes into account the coherence between the carriers and the electromagnetic field. We quantitatively describe the amplitudes and periodicity of FK modulations and the influence of Rydberg excitons on FK effect is also taking into account. Our analytical findings are illustrated numerically for