David Ziemkiewicz

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

Complex Doppler effect in left-handed metamaterials

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Cherenkov radiation combined with the complex Doppler effect in left-handed metamaterials

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.

Optical Properties of Rydberg Excitons and Polaritons

The Doppler shift is investigated in a one-dimensional system with a moving source. Theoretical findings are confirmed by numerical simulations of optical and acoustical wave propagation in a simple metamaterial model, showing the reversed shift and the existence of multiple frequency modes. The properties of these waves are discussed, and the effect of absorption on the phenomenon is outlined.

Frequency shifts of radiating particles moving in EIT metamaterial

A unified analytical description of the Cherenkov and complex Doppler phenomena in a simple metamaterial model is presented. It is shown that a moving monochromatic source generates radiation fields that exhibit features of both Doppler and Cherenkov effects. The theory presented explains many peculiar characteristics of Cherenkov radiation in left-handed metamaterials such as the backward direction of power emission, the constant radiation angle, and the lack of a velocity threshold. The theoretical findings are confirmed by numerical simulations based on the finite-difference time-domain method.

Excitonic spectra of wide parabolic quantum wells

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

We consider the frequency shifts of particles moving in metamaterials exhibiting the electromagnetically induced transparency (EIT) effect. The dramatic change of the material dispersion due to the EIT influences the conditions for signal propagation in the medium and has a significant impact on the Doppler effect, possibly leading to the optical control over this phenomenon. The dependence of the Doppler shift to the source frequency and velocity and radiation spectra on external parameters is examined. It was found that for source frequencies fitting a transparency window for a particular range of source velocities cutoffs appear, i.e., the radiation is not emitted. The analysis of cutoff dependence on the character of medium dispersion brings to light their physical interpretation. Our theoretical findings are proved analytically and confirmed by numerical simulations based on the finite-difference time-domain method.

Tunable narrowband plasmonic resonances in electromagnetically induced transparency media

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.