20,126 research outputs found
Methods for predicting thermal stress cracking in turbine stator or rotor blades Summary report
Test rig for predicting thermal stress cracking in turbine stator or rotor blade
Religion and trust: an experimental study
We investigate the relationship between religion and trust. Using a questionnaire, we measure: i) general religiosity, and; ii) the extent of religious beliefs, experience, and ritual. These are then analyzed with behaviour in a trust game (Berg et al., Games and Economic Behaviour, 1995), which we also extend by proving information of a potential trustee's religiosity in certain tasks. We find that trusting increases with the potential trustee's religiosity. The extent to which trusting increases with a trustee's religiosity, in turn, increases with a truster's religiosity. Trustworthiness also increases with religiosity, and at an increasing rate. --Religiosity,Trust,Stereotype,Questionnaire,Experiment
Generating single-mode behavior in fiber-coupled optical cavities
We propose to turn two resonant distant cavities effectively into one by
coupling them via an optical fiber which is coated with two-level atoms
[Franson et al., Phys. Rev. A 70, 062302 (2004)]. The purpose of the atoms is
to destructively measure the evanescent electric field of the fiber on a time
scale which is long compared to the time it takes a photon to travel from one
cavity to the other. Moreover, the boundary conditions imposed by the setup
should support a small range of standing waves inside the fiber, including one
at the frequency of the cavities. In this way, the fiber provides an additional
decay channel for one common cavity field mode but not for the other. If the
corresponding decay rate is sufficiently large, this mode decouples effectively
from the system dynamics. A single non-local resonator mode is created.Comment: 13 pages, 6 figures, final version, accepted for publicatio
Cavity-assisted spontaneous emission as a single-photon source: Pulse shape and efficiency of one-photon Fock state preparation
Within the framework of exact quantum electrodynamics in dispersing and
absorbing media, we have studied the quantum state of the radiation emitted
from an initially in the upper state prepared two-level atom in a high-
cavity, including the regime where the emitted photon belongs to a wave packet
that simultaneously covers the areas inside and outside the cavity. For both
continuing atom--field interaction and short-term atom--field interaction, we
have determined the spatio-temporal shape of the excited outgoing wave packet
and calculated the efficiency of the wave packet to carry a one-photon Fock
state. Furthermore, we have made contact with quantum noise theories where the
intracavity field and the field outside the cavity are regarded as
approximately representing independent degrees of freedom such that two
separate Hilbert spaces can be introduced.Comment: 16 pages, 7 eps figures; improved version as submitted to Phys. Rev.
Electromagnetic field quantization in a linear polarizable and magnetizable medium
By modeling a linear polarizable and magnetizable medium (magneto-dielectric)
with two quantum fields, namely E and M, electromagnetic field is quantized in
such a medium consistently and systematically. A Hamiltonian is proposed from
which, using the Heisenberg equations, Maxwell and constitutive equations of
the medium are obtained. For a homogeneous medium, the equation of motion of
the quantum vector potential, , is derived and solved analytically.
Two coupling functions which describe the electromagnetic properties of the
medium are introduced. Four examples are considered showing the features and
the applicability of the model to both absorptive and nonabsorptive
magneto-dielectrics.Comment: 23 pages, Accepted for publication in Phy.Rev
Universal measurement of quantum correlations of radiation
A measurement technique is proposed which, in principle, allows one to
observe the general space-time correlation properties of a quantized radiation
field. Our method, called balanced homodyne correlation measurement, unifies
the advantages of balanced homodyne detection with those of homodyne
correlation measurements.Comment: 4 pages, 4 figures, small misprints were corrected, accepted to Phys.
Rev. Let
An analytical solution for the SSFP signal in MRI
Among previous analyses of the steady-state free-precession (SSFP) signal in rapid MRI, one treatment resulted in equations that require the evaluation of infinite binomial series. Here, an analytical solution is derived by a transformation into the power series expansion of the derivative of the inverse sine function, which is essentially a root. The treatment is extended to include higher-order signals. The results demonstrate the identity of the vastly different equations for the SSFP signals reported so far. Applications consist of the derivation of closed expressions for the signal in echo-shifted MRI and a corresponding analysis of TrueFISP sequences. (C) 2003 Wiley-Liss, Inc
Entanglement signature in the mode structure of a single photon
It is shown that entanglement, which is a quantum correlation property of at
least two subsystems, is imprinted in the mode structure of a single photon.
The photon, which is emitted by two coupled cavities, carries the information
on the concurrence of the two intracavity fields. This can be useful for
recording the entanglement dynamics of two cavity fields and for entanglement
transfer.Comment: 4 pages, 3 figure
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