Search results for "Coherence"
showing 10 items of 905 documents
Decoherence of the Exciton and Decay of the Excitonic Polaron in Quantum Dots
2005
Bulk-phonon mechanisms of decoherence of an exciton confined in a quantum dot (QD) are considered in order to establish time limitations for the coherent control of the exciton with relevance to its application in quantum information processing. These are the formation and decay of the excitonic polaron. The estimations of characteristic dephasing times for the InAs/GaAs QD are discussed.
Asymptotic entanglement of two atoms in a squeezed light field
2011
The dynamics of entanglement between two - level atoms interacting with a common squeezed reservoir is investigated. It is shown that for spatially separated atoms there is a unique asymptotic state depending on the distance between the atoms and the atom - photons detuning. In the regime of strong correlations there is a one - parameter family of asymptotic steady - states depending on initial conditions. In contrast to the thermal reservoir both types of asymptotic states can be entangled. We calculate the amount of entanglement in the system in terms of concurrence.
Observation of the condensation of classical waves
2010
We report a theoretical, numerical and experimental study of condensation of classical optical waves. The condensation of observed directly, as a function of nonlinearity and wave kinetic energy, in a self-defocusing photorefractive crystal.
Condensation of classical optical waves
2010
We demonstrate the nonlinear condensation of classical optical waves. The condensation is observed directly, as a function of nonlinearity and wave kinetic energy, in a self-defocusing photorefractive crystal.
Monte Carlo study of cluster-diameter distribution: An observable to estimate correlation lengths
1997
We report numerical simulations of two-dimensional $q$-state Potts models with emphasis on a new quantity for the computation of spatial correlation lengths. This quantity is the cluster-diameter distribution function $G_{diam}(x)$, which measures the distribution of the diameter of stochastically defined cluster. Theoretically it is predicted to fall off exponentially for large diameter $x$, $G_{diam} \propto \exp(-x/\xi)$, where $\xi$ is the correlation length as usually defined through the large-distance behavior of two-point correlation functions. The results of our extensive Monte Carlo study in the disordered phase of the models with $q=10$, 15, and $20$ on large square lattices of si…
On general conditional prevision assessments
2009
In this paper we consider general conditional random quantities of the kind $X|Y$, where $X$ and $Y$ are finite discrete random quantities. Then, we introduce the notion of coherence for conditional prevision assessments on finite families of general conditional random quantities. Moreover, we give a compound prevision theorem and we examine the relation between the previsions of $X|Y$ and $Y|X$. Then, we give some results on random gains and, by a suitable alternative theorem, we obtain a characterization of coherence. We also propose an algorithm for the checking of coherence. Finally, we briefly examine the case of imprecise conditional prevision assessments by introducing the notions of…
Planning Control on the Northern European Periphery
2010
From different pasts and currently different connections to EU, Latvia and Norway in the last few years have created new legal frameworks for their national planning systems and hence for planning control. This paper explores similarities and differences between these two planning control systems and related tendencies in the revision of planning legislation adopted in recent times. Methodologically, the study makes a distinction between acting organizational subjects and the rules of the game that affect their performance. Together with the planning organization, such formal institutional factors indicate modes of planning control as well as possibilities for creating coherence across plan…
El sistema de continuidad como proceso unificador
2007
El sistema de continuidad es un procedimiento de construcción de relatos audiovisuales que tiene como fundamento la causalidad narrativa y un conjunto de normas de elaboración, especialmente en el montaje, cuya finalidad es mostrar al espectador un desarrollo argumental lógico que se desarrolla en un espacio-tiempo diegético coherente. La continuidad, está sometida a un modelo ideológico de representación que condiciona la percepción. La continuidad no es, por lo tanto, un concepto absoluto, sino que evoluciona a lo largo del tiempo. Sin embargo, el sistema de continuidad permanece vigente porque garantiza el predominio de la cadena causal y la inmersión del espectador en el universo diegét…
“In situ” corneal and contact lens thickness changes with high resolution OCT
2012
Purpose: To show the utility of high resolution spectral domain optical coherence tomography (HR SOCT) for the in situ evaluation of epithelial, stromal and contact lens (CL) thickness changes under closed-eye conditions without lens removal. Settings: Clinical and Experimental Optometry Research Lab, University of Minho, Portugal. Methods: Eight young healthy patients wore a thick soft CL during 90 minutes under closed-eye conditions and measures of epithelial and stromal corneal thickness were obtained at regular intervals using a HR SOCT (Copernicus HR, Optopol Tech. SA, Poland). Results: Minimal changes in epithelial thickness were detected with a transient statistically significant inc…
Response by Meneveau and Ecarnot to Letter Regarding Article, “Optical Coherence Tomography to Optimize Results of Percutaneous Coronary Intervention…
2017
We read with interest the letters by Vallurupalli and Uretsky and also Dr Nadir relating to the results of the DOCTORS study (Does Optical Coherence Tomography Optimize Results of Stenting).1 We thank the authors for their insightful remarks. Vallurupalli and Uretsky raise an interesting point when they underline that a prolonged inflation time is superior to a rapid inflation/deflation technique in terms of both stent expansion and apposition. We acknowledge that we did not take stent inflation time into account in the case report form of the DOCTORS study. The arguments put forward by Vallurupalli and Uretsky suggest that this variable should be systematically recorded and reported. Howev…