Localization of one-photon state in space and Einstein-Podolsky-Rosen paradox in spontaneous parametric down conversion

An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function

Nondestructive measurement of intensity of optical fields using spontaneous parametric down conversion

Results of nondestructive measurements of intensity (photons per mode) of light from different sources are discussed. The procedure of measurement does not destroy the state of the optical field. The method is based on using the second order nonlinearity of crystal media lacking a center of symmetry and the nonclassical properties of the process of Spontaneous Parametric Down Conversion (SPDC)

Data assimilation using a hybrid ice flow model

Hybrid models, or depth-integrated flow models that include the effect of both longitudinal stresses and vertical shearing, are becoming more prevalent in dynamical ice modeling. Under a wide range of conditions they closely approximate the well-known First Order stress balance, yet are of computationally lower dimension, and thus require less intensive resources. Concomitant with the development and use of these models is the need to perform inversions of observed data. Here, an inverse control method is extended to use a hybrid flow model as a forward model. We derive an adjoint of a hybrid model and use it for inversion of ice-stream basal traction from observed surface velocities. A novel aspect of the adjoint derivation is a retention of non-linearities in Glen's flow law. Experiments show that in some cases, including those nonlinearities is advantageous in minimization of the cost function, yielding a more efficient inversion procedure

Performance of Photon-Pair Quantum Key Distribution Systems

We analyze the quantitative improvement in performance provided by a novel quantum key distribution (QKD) system that employs a correlated photon source (CPS) and a photon-number resolving detector (PNR). Our calculations suggest that given current technology, the CPR implementation offers an improvement of several orders of magnitude in secure bit rate over previously described implementations

Two-Photon Spiral Imaging with Correlated Orbital Angular Momentum States

The concept of correlated two-photon spiral imaging is introduced. We begin by analyzing the joint orbital angular momentum (OAM) spectrum of correlated photon pairs. The mutual information carried by the photon pairs is evaluated, and it is shown that when an object is placed in one of the beam paths the value of the mutual information is strongly dependent on object shape and is closely related to the degree of rotational symmetry present. After analyzing the effect of the object on the OAM correlations, the method of correlated spiral imaging is described. We first present a version using parametric downconversion, in which entangled pairs of photons with opposite OAM values are produced, placing an object in the path of one beam. We then present a classical (correlated, but non-entangled) version. The relative problems and benefits of the classical versus entangled configurations are discussed. The prospect is raised of carrying out compressive imaging via twophoton OAM detection to reconstruct sparse objects with few measurements

Constitutive and numerical modeling of chemical and mechanical phenomena in thermal barrier coatings for gas turbine blades of aircraft engines

Виконано моделювання хімічних і механічних явищ, та розроблені узагальнені визначальні співвідношення, які можуть бути використано для розрахунків залежних від часу розподілень напружень та пошкоджуваності термоізоляції лопаток газових турбін авіаційних двигунів. Розроблені визначальні співвідношення впроваджено в формі структурних моделей для аналізу пошкоджуваності в часі термоізоляції лопаток газових турбін авіаційних двигунів, для аналізу міцності та тривалої міцності, для забезпечення безпечної роботи лопаток газових турбін авіаційних двигунів

An investigation of the parametric X-ray along the velocity of emitting particle

Parametric X-rays (PXR) along the velocity of relativistic electrons crossing a crystalline target is studied in this work. The detailed theory of PXRfor Laue scattering geometry is developed with account of contributions of both PXRand transition radiation (TR) to the total emission yield. An influence of photoabsorption and interference between PXRand TRon the forward PXR properties are studied. Most appropriate conditions for the real experiment devoted to forward PXRobservation are elucidated on the basis of the developed theory. The advantage of the use of heavy crystals with this aim in mind is shown. The expected experimental results are discussedyesBelgorod State Universit

On the issue of the development of domestic tourism in the Russian Federation

The article considers the problematic issues of the development of the tourism industry in the Russian Federation. In the context of global challenges, the tourism sector of the Russian Federation retains significant potential to accelerate growth and strengthen its role in the development of the economy. On the example of individual tourist projects, the author summarizes and identifies possible areas of activity of public authorities. The study makes comprehensive proposals for the development of the tourist destination at the territorial level, including in the preparation of strategic documents, the adoption of regulatory measures on the business activities of the self-employed in the tourism sector, increasing the revenue base of local budgets through the development of tourism through the introduction of an additional fee

Odd-Order Aberration-Cancellation in Correlated-Photon Imaging

We discuss a correlated two-photon imaging apparatus that is capable of producing images that are free of the effects of odd-order aberration introduced by the optical system. We show that both quantum-entangled and classically correlated light sources are capable of producing the desired spatial-aberration cancelation