1,021 research outputs found
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
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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
Temperature dependence of the electron spin g factor in GaAs
The temperature dependence of the electron spin factor in GaAs is
investigated experimentally and theoretically. Experimentally, the 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 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
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 factor with the temperature is predominantly due to
band's nonparabolicity.Comment: 6 pages 4 figure
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
Standard constitutional catalog of principles of judicial authority in the CIS countries
The present paper presents the results of a comparative legal analysis of constitutions of the CIS member states in order to identify a standard catalog of judicial power principles in them, considering their interpretation as a set of fundamental principles determining the institutional and procedural aspects of judicial powe
EIT and diffusion of atomic coherence
We study experimentally the effect of diffusion of Rb atoms on
Electromagnetically Induced Transparency (EIT) in a buffer gas vapor cell. In
particular, we find that diffusion of atomic coherence in-and-out of the laser
beam plays a crucial role in determining the EIT resonance lineshape and the
stored light lifetime.Comment: 5 pages, 8 figure
Homogeneous singularities inside collapsing wormholes
We analyze analytically and numerically the origin of the singularity in the
course of the collapse of a wormhole with the exotic scalar field Psi with
negative energy density, and with this field Psi together with the ordered
magnetic field H. We do this under the simplifying assumptions of the spherical
symmetry and that in the vicinity of the singularity the solution of the
Einstein equations depends only on one coordinate (the homogeneous
approximation). In the framework of these assumptions we found the principal
difference between the case of the collapse of the ordinary scalar field Phi
with the positive energy density together with an ordered magnetic field H and
the collapse of the exotic scalar field Psi together with the magnetic field H.
The later case is important for the possible astrophysical manifestation of the
wormholes.Comment: 10 pages, 5 figures each of which has a),b),c),and d) sub-figures. To
be published in "Physical review. D, Particles, fields, gravitation, and
cosmology
Vacuum Squeezing in Atomic Media via Self-Rotation
When linearly polarized light propagates through a medium in which
elliptically polarized light would undergo self-rotation, squeezed vacuum can
appear in the orthogonal polarization. A simple relationship between
self-rotation and the degree of vacuum squeezing is developed. Taking into
account absorption, we find the optimum conditions for squeezing in any medium
that can produce self-rotation. We then find analytic expressions for the
amount of vacuum squeezing produced by an atomic vapor when light is
near-resonant with a transition between various low-angular-momentum states.
Finally, we consider a gas of multi-level Rb atoms, and analyze squeezing for
light tuned near the D-lines under realistic conditions.Comment: 10 pages, 6 figures; Submitted to PR
Magnetic field imaging with atomic Rb vapor
We demonstrate the possibility of dynamic imaging of magnetic fields using
electromagnetically induced transparency in an atomic gas. As an experimental
demonstration we employ an atomic Rb gas confined in a glass cell to image the
transverse magnetic field created by a long straight wire. In this arrangement,
which clearly reveals the essential effect, the field of view is about 2 x 2
mm^2 and the field detection uncertainty is 0.14 mG per 10 um x 10 um image
pixel.Comment: 4 pages, 3 figure
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