Observation of polarization quantum noise of laser radiation in Rb vapor cell

We present experimental study of polarization quantum noise of laser radiation passed through optically think vapor of Rb87. We observe a step-like noise spectrum. We discuss various factor which may result in such noise spectrum and prevent observation of squeezing of quantum fluctuations predicted in Matsko et al. PRA 63, 043814 (2001).Comment: 4 pages, 5 figures. Translated from Russian by I. Novikov

Enhancement of Kerr nonlinearity via multi-photon coherence

We propose a new method of resonant enhancement of optical Kerr nonlinearity using multi-level atomic coherence. The enhancement is accompanied by suppression of the other linear and nonlinear susceptibility terms of the medium. We show that the effect results in a modification of the nonlinear Faraday rotation of light propagating in an Rb87 vapor cell by changing the ellipticity of the light.Comment: 4 pages, 3 figures Submitted to Optics Letter

Temperature dependence of the electron spin g factor in GaAs

The temperature dependence of the electron spin $g$ factor in GaAs is investigated experimentally and theoretically. Experimentally, the $g$ factor was measured using time-resolved Faraday rotation due to Larmor precession of electron spins in the temperature range between 4.5 K and 190 K. The experiment shows an almost linear increase of the $g$ value with the temperature. This result is in good agreement with other measurements based on photoluminescence quantum beats and time-resolved Kerr rotation up to room temperature. The experimental data are described theoretically taking into account a diminishing fundamental energy gap in GaAs due to lattice thermal dilatation and nonparabolicity of the conduction band calculated using a five-level kp model. At higher temperatures electrons populate higher Landau levels and the average $g$ factor is obtained from a summation over many levels. A very good description of the experimental data is obtained indicating that the observed increase of the spin $g$ factor with the temperature is predominantly due to band's nonparabolicity.Comment: 6 pages 4 figure

The New Normal: The Resurgence of Activist Investing Since the End of the Financial Crisis

ince 2010 there has been an incredible inflow of capital to hedge funds that focus specifically on activist investing. The aggressive and often hostile actions of activist funds have created negative publicity and an increased focus on the shortened holding period of these investors. But are activists a blessing or a curse? This report, produced by the M&A Research Centre (MARC) at Cass Business School provides an insight into the short- and long-term performance effects of activist campaigns in the United States, Germany, and the United Kingdom since the financial crisis. This report should not be considered as a guide for activist investors on what tactics to use or a guide for company executives on what they should be prepared for. It rather highlights important patterns in the outcomes of shareholder activism in the United States, Germany, and United Kingdom since the beginning of 2010, when the economies of these countries were emerging from the depths of the financial crisis. Activism tends to be concentrated largely in the United States, but the expectations for further expansion into Europe make it important to understand its existing environment and what activist methods have had success in the region. As equity markets reach new heights in Europe, there will be new opportunities for activist investors

X-ray-absorption fine-structure study of ZnSexTe1−x alloys

X-ray-absorption fine-structure experiments at different temperatures in ZnSexTe1−x (x=0, 0.1, 0.2, 0.55, 0.81, 0.93, 0.99, and 1.0) have been performed in order to obtain information about the structural relaxation and disorder effects occurring in the alloys. First and second neighbor distance distributions have been characterized at the Se and Zn K edges, using multiple-edge and multiple-scattering data analysis. The first neighbor distance distribution was found to be bimodal. The static disorder associated with the Zn–Te distance variance did not depend appreciably on composition. On the other hand, the static disorder associated with the Zn–Se distance increased as the Se content diminished. Using the bonding angle information provided by our experiments the point of view of the anion has been related to that of the cation. The resulting structural model indicates that Zn tetrahedra surrounding the anions remain essentially undistorted, but forced to tilt from their ideal zincblende orientation to accommodate the minority element. The main origin of structural disorder is [email protected] ; [email protected]

Scenarios of increasing the econo­mic efficiency of the Kaliningrad regional transport system

The development of the considerable transport and logistics potential of the Kaliningrad region is hampered by several factors. This problem, to which we will refer to as a transport deadlock effect, translates into the limited contribution of transport to the regional economy. Particularly, it manifests itself at the level of regional gross value added, where the contribu­tion of transport is much smaller than one might expect given the significant role the industry plays in the economy of the region. In this study, we examine major ways of increasing the economic efficiency of the regional transport system from the value added perspective. We posit that the structure of cargo handled and the redistribution of value added in favour of regional actors have the dominant influence on economic efficiency. Using our own simula­tion model and the earlier developed system of transport tariffs and value added calculation for the Kaliningrad region, we produce scenarios and consider changes in value added in the case of selected cargoes carrying intermediate, investment, and consumer goods (as defined in the International Classification for Broad Economic Categories ICT BEC-4). Our calcula­tions show that higher value added and greater economic efficiency of a regional transport system are associated with re-orientation towards investment and consumer goods. The most visible effect is associated with rail and road transport. As to sea transport, the decisive role is played by an increase in the physical volume of cargo handled. The results of this study and its modelling tools can be applied in the analysis of the current situation and in the assess­ment of the efficiency of transport systems in other regions. Another possible application is the identification of growth conditions for an industry, particularly, when developing projects and proposals for increasing the efficiency of transport services

Dynamic optical bistability in resonantly enhanced Raman generation

We report observations of novel dynamic behavior in resonantly-enhanced stimulated Raman scattering in Rb vapor. In particular, we demonstrate a dynamic hysteresis of the Raman scattered optical field in response to changes of the drive laser field intensity and/or frequency. This effect may be described as a dynamic form of optical bistability resulting from the formation and decay of atomic coherence. We have applied this phenomenon to the realization of an all-optical switch.Comment: 4 pages, 5 figure

Justice independence: foreign constitutional experiences

This article presents the results of a comparative legal study investigating the norms of constitution in CIS countries, Europe and America about formalizing the principle of justice independenc