Wannier-Stark effect and electron-phonon interaction in macroporous silicon structures with SiO2 nanocoatings

2014 ◽  
Vol 22 (4) ◽  
Author(s):  
L. Karachevtseva ◽  
Yu. Goltviansky ◽  
O. Kolesnyk ◽  
O. Lytvynenko ◽  
O. Stronska
Keyword(s):  
Electron Scattering ◽  
Stark Effect ◽  
Oscillation Amplitude ◽  
Level Energy ◽  
Ir Absorption ◽  
Macroporous Silicon ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Silicon Structures ◽  
Resonance Electron

AbstractWe investigated the contribution of electron-phonon interaction to the broadening parameter Γ of the Wannier-Stark ladder levels in oxidized macroporous silicon structures with different concentration of Si-O-Si states (TO and LO phonons). The obtained value of the Wannier-Stark ladder parameter Γ is much less than the djacent level energy evaluated from giant oscillations of resonance electron scattering on the surface states. We determined the influence of broadening on the oscillation amplitude in IR absorption spectra as interaction of the surface multi-phonon polaritons with scattered electrons. This interaction transforms the resonance electron scattering in samples with low concentration of Si-O-Si states into ordinary scattering on ionized impurities for samples with high concentration of Si-O-Si states. The transformation takes place at the scattering lifetime coinciding with the period of electron oscillations in the surface electric field.

scholarly journals Influence of electron-phonon interaction on wannier–stark effect in macroporous silicon structures with SiO2 nanocoatings

2015 ◽  
Vol 5 (1) ◽  
pp. 3-9
Author(s):  
L.A. Karachevtseva ◽  
◽  
Yu.V. Goltviansky ◽  
O.Yu. Sapelnikova ◽  
O.O. Lytvynenko ◽  
...  
Keyword(s):  
Stark Effect ◽  
Macroporous Silicon ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Silicon Structures

scholarly journals Exciton-polaritons in 2d macroporous silicon structures with nano-coatings

2020 ◽  
Vol 11 (4) ◽  
pp. 445-455
Author(s):  
L. A. Karachevtseva ◽  
◽  
O. O. Lytvynenko ◽  
V. F. Onyshchenko ◽  
V. V. Strelchuk ◽  
...  
Keyword(s):  
Large Scale ◽  
Oscillation Period ◽  
Einstein Condensation ◽  
Ir Absorption ◽  
Reflection Spectra ◽  
Macroporous Silicon ◽  
Band Bending ◽  
Surface Polaritons ◽  
Exciton Polaritons ◽  
Silicon Structures

In this paper, we investigated high-resolution IR absorption and reflection spectra in one-sided periodical 2D macroporous silicon structures with nano-coatings of SiO2 and CdS, ZnO nanoparticles, as well as two-sided structures of macroporous silicon without nano-coatings. After changing the resolution of spectra measurements from 2 to 1 cm–1, the oscillation period of Wannier-Stark electro-optical effect decreases by 3 times, and absorption increases by 60–100 times; and for two-sided structures the oscillation period decreases by 1.5 times and absorption increases by 25–30 %. In addition, giant absorption oscillations with positive and negative amplitudes of 107 arb. un. were evaluated in spectral regions of Si–Si–bonds and Pb centers. Similar oscillations in the reflection spectra have much less amplitudes up to 4·104 arb. un. In the spectral area of the transverse phonon ωTO (Si–Si–bonds) absorption spectra of 2D macroporous silicon structures consistent fully with data for phonon polaritons in microresonators as a result of resonance interaction of dipole-active vibrations with the frequency of ωTO in thin films with the surface modes of microresonator. In addition, microresonators interact both with each other in one-sided macroporous silicon structures and in the system of two-sided macroporous silicon. The giant absorption oscillations testify the strong interaction of surface polaritons with photons. The coherence of oscillations and large-scale spatial correlation are а result of exciton-polariton condensation on macropores as microresonators. In 2D macroporous silicon structures with nano-coatings band bending on the surface of the macropores are significant. Therefore, the generated photoelectrons link with holes, forming electron-hole pairs named as exciton-polaritons according to phenomenon of Bose-Einstein condensation.

scholarly journals Electron-Phonon Scattering in Quantum-Sized Films with the Hyperbolic Pöschl–Teller Potential

2019 ◽  
Vol 64 (4) ◽  
pp. 336
Author(s):  
Kh. A. Gasanov ◽  
J. I. Guseinov ◽  
I. I. Abbasov ◽  
D. J. Askerov ◽  
Kh. O. Sadig
Keyword(s):  
Electron Scattering ◽  
Phonon Scattering ◽  
Transition Probability ◽  
Bulk Crystals ◽  
Dimensional Electron ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Dimensional Electron Gas ◽  
Analytical Expressions ◽  
Electron Phonon Scattering

A quantitative theory of electron-phonon interaction in the two-dimensional electron gas in a quantum-sized film with the hyperbolic P¨oschl–Teller confining potential has been developed. Analytical expressions for the transition probability are derived in the case of electron scattering by deformation-induced acoustic, piezoacoustic, and polar optical phonons. The results obtained for various scattering mechanisms in the film are compared with the results obtained for bulk crystals.

CORRELATION EFFECTS AND ELECTRON-PHONON INTERACTION IN DOPED FULLERITE

1993 ◽  
Vol 07 (27) ◽  
pp. 1733-1739 ◽  
Author(s):  
VALERY IVANOV ◽  
RENATO PUCCI ◽  
VLADIMIR YARUNIN
Keyword(s):  
Experimental Data ◽  
Electron Scattering ◽  
Low Frequency ◽  
Superconducting Gap ◽  
Correlation Effects ◽  
Phonon Modes ◽  
Phonon Interaction ◽  
Atom Concentration ◽  
Electron Phonon Interaction

We propose a model for A x C 60 systems involving both Hubbard repulsion of alkali electrons in the narrow LUMO band of C 60 and their interaction with both high- and low-frequency phonon modes. In our approach, these phonons play different roles in the determination of a nonzero interband hopping integral hp, which increases the value of the superconductive critical temperature T c . A nonadiabatical approximation is used for the calculation of the soft-phonon-electron scattering. In the framework of the Gor’kov method and the kinematical high-T c mechanism, we have obtained an expression for T c as a function of the A atom concentration x and found that the superconducting gap Δ0 satisfies the inequality 2Δ0/T c >3.53. The qualitative agreements with experimental data were obtained.

scholarly journals 1D and 2D polaritons in macroporous silicon structures with nano-coatings

2021 ◽  
Vol 12 (1) ◽  
pp. 9-17
Author(s):  
L. A. Karachevtseva ◽  
◽  
M. T. Kartel ◽  
O. O. Lytvynenko ◽  
◽  
...  
Keyword(s):  
High Resolution ◽  
Polarized Light ◽  
Destructive Interference ◽  
Ir Absorption ◽  
Macroporous Silicon ◽  
Additional Degree ◽  
Two Photon ◽  
Ir Absorption Spectra ◽  
Silicon Structures ◽  
Photon States

In this paper, we used high-resolution IR absorption spectra to investigate 1D and 2D polaritons in periodical 2D macroporous silicon structures with nano-coatings of SiO2 and CdS, ZnO nanoparticles. The application of high-resolution IR absorption spectroscopy resulted in detection of dipole-active TO vibrations, photon splitting and giant two-polar absorption oscillations with amplitudes of ±107arb.un. As a result, the dispersion law in yz surfaces of macropores change to z direction along macropores. It means additional degree of freedom as vertically polarized light in z direction and horizontally polarized light in x direction resulted in beams splitting and two-photon interference - Hong-Ou-Mandel effect. In our case, 2D resonances of Wannier-Stark electro-optical effect in yz plane correspond to constructive interference of the two-photon states (bosonic behavior), and two-polar resonances in ±z direction are determined by destructive interference of the two-photon states (fermionic behavior). Two-polar oscillations of 1D -polaritons have the ultra-small half-width 0.4–0.6 сm–1 and minimal Rabi frequency of samples 1.0 сm–1 equaled to the resolution of spectral measurements. Furthermore, two-photon interference and 1D polaritons are perspective for high-coherent optical quantum computers on macroporous silicon with nano-coatings and, in addition, for lasers and new metamaterials.

The simulation of the electron-phonon interaction in silicon

2018 ◽  
Vol 30 (12) ◽  
pp. 3-16
Author(s):  
A. Berezin ◽  
◽  
Yu. Volkov ◽  
M. Markov ◽  
I. Tarakanov ◽  
...  
Keyword(s):  
Phonon Interaction ◽  
Electron Phonon Interaction
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