2,387 research outputs found
Different regimes of Forster energy transfer between an epitaxial quantum well and a proximal monolayer of semiconductor nanocrystals
We calculate the rate of non-radiative, Forster-type energy transfer (ET)
from an excited epitaxial quantum well (QW) to a proximal monolayer of
semiconductor nanocrystal quantum dots (QDs). Different electron-hole
configurations in the QW are considered as a function of temperature and
excited electron-hole density. A comparison of the theoretically determined ET
rate and QW radiative recombination rate shows that, depending on the specific
conditions, the ET rate is comparable to or even greater than the radiative
recombination rate. Such efficient Forster ET is promising for the
implementation of ET-pumped, nanocrystal QD-based light emitting devices.Comment: 14 pages, 4 figure
Thermodynamics and Excitations of Condensed Polaritons in Disordered Microcavities
We study the thermodynamic condensation of microcavity polaritons using a
realistic model of disorder in semiconductor quantum wells. This approach
correctly describes the polariton inhomogeneous broadening in the low density
limit, and treats scattering by disorder to all orders in the condensed regime.
While the weak disorder changes the thermodynamic properties of the transition
little, the effects of disorder in the condensed state are prominent in the
excitations and can be seen in resonant Rayleigh scattering.Comment: 5 pages, 3 eps figures (published version
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Identifying causal gateways and mediators in complex spatio-temporal systems
Statistical Mechanics and Information-Theoretic Perspectives on Complexity in the Earth System
Peer reviewedPublisher PD
Non-circular semiconductor nanorings of type I and II: Emission kinetics in the exciton Aharonov-Bohm effect
Transition energies and oscillator strengths of excitons in dependence on
magnetic field are investigated in type I and II semiconductor nanorings. A
slight deviation from circular (concentric) shape of the type II nanoring gives
a better observability of the Aharonov-Bohm oscillations since the ground state
is always optically active. Kinetic equations for the exciton occupation are
solved with acoustic phonon scattering as the major relaxation process, and
absorption and luminescence spectra are calculated showing deviations from
equilibrium. The presence of a non-radiative exciton decay leads to a quenching
of the integrated photoluminescence with magnetic field.Comment: The first version submitted to Phys. Rev. B on April 16, 2007.
Revised (this) version on July 31, 200
EarthNet2021: A large-scale dataset and challenge for Earth surface forecasting as a guided video prediction task
The design features of the body of the portable electrocardiograph "ECG-EXPRESS"
The sequence of the industrial product shaping is specified, the main modeling characteristics of the configuration and some of its parts are designated subject to the electrocardiograph design and the technologies used for the production of its body
Effect of inter-wall surface roughness correlations on optical spectra of quantum well excitons
We show that the correlation between morphological fluctuations of two
interfaces confining a quantum well strongly suppresses a contribution of
interface disorder to inhomogeneous line width of excitons. We also demonstrate
that only taking into account these correlations one can explain all the
variety of experimental data on the dependence of the line width upon thickness
of the quantum well.Comment: 13 pages, 8 figures, Revtex4, submitted to PR
Commensurate and Incommensurate Vortex States in Superconductors with Periodic Pinning Arrays
As a function of applied field, we find a rich variety of ordered and
partially-ordered vortex lattice configurations in systems with square or
triangular arrays of pinning sites. We present formulas that predict the
matching fields at which commensurate vortex configurations occur and the
vortex lattice orientation with respect to the pinning lattice. Our results are
in excellent agreement with recent imaging experiments on square pinning arrays
[K. Harada et al., Science 274, 1167 (1996)].Comment: 9 pages, 3 figures. Accepted to Physical Review
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