Results
author = "Vasilevskiy, Mikhail"
Dipolar vibrational modes in spherical semiconductor quantum dots
Author(s) :
Vasilevskiy, Mikhail
Description :
Spatially quantized dipolar phonon modes in a spherical quantum dot ~QD! made of a polar isotropic material are considered in the framework of a continnum model. Different mechanical boundary conditions are
analyzed, which are shown to strongly influence the spectrum of the dipole-active modes. The ...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
Effective dielectric response of semiconductor composites
Description :
Using a previously proposed diagrammatic approach for the calculation of the renormalized polarizability of spherical inclusions in a homogeneous matrix we obtain an effective dielectric response of a composite of nonpercolating inclusions taking into account a continuous distribution of sizes of th...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
Polaron relaxation in a quantum dot due to anharmonic coupling within a mean-field approach
Description :
We study the electronic relaxation in a quantum dot within the polaron approach by focusing on the
reversible anharmonic decay of longitudinal optical LO phonons forming the polaron into longitudinalacoustic
LA phonons. The coherent coupling between the LO and LA phonons is treated within a mean...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
Resonant excitation of confined excitons in nanocrystal quantum dots using surface plasmon-polaritons
Description :
Surface plasmon-polaritons (SPPs) in a multilayer
structure consisting of a metallic film and one or more layers of
nanocrystal (NC) quantum dots (QDs) are studied theoretically. It
is shown that there is a resonance coupling between the plasmonpolaritons
propagating along the metal/NC-layer interfa...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
Electron-phonon interaction effects in semiconductor quantum dots: a non-perturbative approach
Description :
Multiphonon processes in a model quantum dot (QD) containing two electronic states and several optical phonon modes are considered by taking into account both intra- and nterlevel terms. The Hamiltonian is exactly diagonalized, including a finite number of multiphonon processes large enough to guar...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
Is polaron effect important for resonant Raman scattering in self-assembled quantum dots?
Description :
While the diagonal (or intra-level) interaction of a confined exciton with optical phonons in selfassembled quantum dots (SAQD’s) is rather weak, the non-diagonal one can lead to a considerable change of the exciton spectrum and the formation of a polaron. An impact of this effect on resonant inelas...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
Graphene-based polaritonic crystal
Description :
It is shown that monolayer graphene deposited on a spatially periodic gate behaves as a polaritonic crystal. Its band structure depending on the applied gate voltage is studied. The scattering of electromagnetic radiation from such a crystal is presented calculated and its spectral dependence is ana...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
Tunable graphene-based polarizer
Description :
It is shown that an attenuated total reflection structure containing a graphene layer can operate as a tunable polarizer of the electromagnetic radiation. The polarization of the reflected electromagnetic wave is controlled by adjusting the voltage applied to graphene via external gate, as demonstra...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
Exciton states in free-standing and embedded semiconductor nanocrystals
Author(s) :
Núñez Fernández, Yuriel
,
Vasilevskiy, Mikhail
,
Larramendi, Erik
,
Trallero-Giner, Carlos
Description :
the effects of surrounding media (shells and matrix) and interface characteristics on the
exciton ground state in nanocrystal QDs that would be able to explain the above mentioned
experimental results and could be applied to more sophisticated semiconductor structures
based on NCs of an approximatel...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English
One-phonon Raman scattering from arrays of semiconductor nano-crystals
Description :
We re-consider Raman scattering by LO-type phonons in a small semiconductor crystal and derive a simple formula taking into account the higher order confined phonon modes, to describe the asymmetric Raman lineshapes observed experimentally. For a single crystalline sphere, we explicitly calculate th...
Repository :
RepositóriUM - University of Minho Institutional Repository
Language(s) :
English