10,151 research outputs found
Thermal effects on the resonance fluorescence of doubly dressed artificial atoms
In this work, robustness of controlled density of optical states in doubly
driven artificial atoms is studied under phonon dissipation. By using both
perturbative and polaron approaches, we investigate the influence of
carrier-phonon interactions on the emission properties of a two-level
solid-state emitter, simultaneously coupled to two intense distinguishable
lasers. Phonon decoherence effects on the emission spectra are found modest up
to neon boiling temperatures ( K), as compared with photon generation
at the Fourier transform limit obtained in absence of lattice vibrations (zero
temperature). These results show that optical switching and photonic modulation
by means of double dressing, do not require ultra low temperatures for
implementation, thus boosting its potential technological applications.Comment: Submitted versio
Composite Fading Models based on Inverse Gamma Shadowing: Theory and Validation
We introduce a general approach to characterize composite fading models based
on inverse gamma (IG) shadowing. We first determine to what extent the IG
distribution is an adequate choice for modeling shadow fading, by means of a
comprehensive test with field measurements and other distributions
conventionally used for this purpose. Then, we prove that the probability
density function and cumulative distribution function of any IG-based composite
fading model are directly expressed in terms of a Laplace-domain statistic of
the underlying fast fading model and, in some relevant cases, as a mixture of
wellknown state-of-the-art distributions. Also, exact and asymptotic
expressions for the outage probability are provided, which are valid for any
choice of baseline fading distribution. Finally, we exemplify our approach by
presenting several application examples for IG-based composite fading models,
for which their statistical characterization is directly obtained in a simple
form.Comment: This work has been submitted to the IEEE for publication. Copyright
may be transferred without notice, after which this version may no longer be
accessibl
Effective Polynomial Ballisticity Condition for Random Walk in Random Environment
The conditions which have been introduced
by Sznitman in 2002, have had a significant impact on research in random walk
in random environment. Among others, these conditions entail a ballistic
behaviour as well as an invariance principle. They require the stretched
exponential decay of certain slab exit probabilities for the random walk under
the averaged measure and are asymptotic in nature.
The main goal of this paper is to show that in all relevant dimensions (i.e.,
), in order to establish the conditions , it is actually
enough to check a corresponding condition of polynomial type.
In addition to only requiring an a priori weaker decay of the corresponding
slab exit probabilities than another advantage of the condition
is that it is effective in the sense that it can be checked on
finite boxes.
In particular, this extends the conjectured equivalence of the conditions
to all relevant dimensions.Comment: 21 pages, 2 figures; followed referee's and readers' comments,
corrected minor errors; to appear in Comm. Pure Appl. Mat
- …