3,058 research outputs found
Emergent Radiation in an Atom-Field System at Twice-Resonance
A two-level atom interacting with a single mode of quantized electromagnetic
radiation is discussed using a representation in which the atom and the
radiation are unified into a {\em new} canonical radiation. At the {\em
twice-resonance}, when the frequency of the original radiation is twice the
atomic transition frequency (), the {\em emergent} unified
field in the non-interacting atom-field system resembles a free radiation of
frequency . This free emergent radiation is further shown to exist in
the presence of an interaction which looks similar to the atom-field
interaction in the dipole approximation. The one-photon correlation and the
population inversion are discussed as the possible means of observing the
emergent radiation. The entanglement properties of the emergent radiation are
also discussed.Comment: 4+ pages, 2 figures, submitted for publication; included a discussion
on the entanglemen
Factors Used to Determine the Teaching Load for Chairs in Public Community Colleges
After a 10 minute presentation of a recently completed national study of the practices used by public community colleges to determine chair teaching load, attendees will be provided a framework and procedure for determining chair teaching load on their campus, and will then engage in a spirited but structured discussion of the factors to be considered and a process for assigning weights to each
Bose-Einstein condensation of trapped interacting spin-1 atoms
We investigate Bose-Einstein condensation of trapped spin-1 atoms with
ferromagnetic or antiferromagnetic two-body contact interactions. We adopt the
mean field theory and develop a Hartree-Fock-Popov type approximation in terms
of a semiclassical two-fluid model. For antiferromagnetic interactions, our
study reveals double condensations as atoms in the state never seem
to condense under the constraints of both the conservation of total atom number
and magnetization . For ferromagnetic interactions, however, triple
condensations can occur. Our results can be conveniently understood in terms of
the interplay of three factors: (anti) ferromagnetic atom-atom interactions,
conservation, and the miscibilities between and among different condensed
components.Comment: RevTex 4, 9 pages, 5 eps figures, to appear in Phys. Rev. A, vol 70,
p
Supersensitive measurement of angular displacements using entangled photons
We show that the use of entangled photons having non-zero orbital angular
momentum (OAM) increases the resolution and sensitivity of angular-displacement
measurements performed using an interferometer. By employing a 44
matrix formulation to study the propagation of entangled OAM modes, we analyze
measurement schemes for two and four entangled photons and obtain explicit
expressions for the resolution and sensitivity in these schemes. We find that
the resolution of angular-displacement measurements scales as while the
angular sensitivity increases as , where is the number of
entangled photons and the magnitude of the orbital-angular-momentum mode
index. These results are an improvement over what could be obtained with
non-entangled photons carrying an orbital angular momentum of per
photonComment: 6 pages, 3 figure
Adiabatic loading of a Bose-Einstein condensate in a 3D optical lattice
We experimentally investigate the adiabatic loading of a Bose-Einstein
condensate into an optical lattice potential. The generation of excitations
during the ramp is detected by a corresponding decrease in the visibility of
the interference pattern observed after free expansion of the cloud. We focus
on the superfluid regime, where we show that the limiting time scale is related
to the redistribution of atoms across the lattice by single-particle tunneling
Precision quantum metrology and nonclassicality in linear and nonlinear detection schemes
We examine whether metrological resolution beyond coherent states is a
nonclassical effect. We show that this is true for linear detection schemes but
false for nonlinear schemes, and propose a very simple experimental setup to
test it. We find a nonclassicality criterion derived from quantum Fisher
information.Comment: 4 pages, 1 figur
Entanglement measurement of the quadrature components without the homodyne detection in the spatially multi-mode far-field
We consider the measuring procedure that in principle allows to avoid the
homodyne detection for the simultaneous selection of both quadrature components
in the far-field. The scheme is based on the use of the coherent sources of the
non-classical light. The possibilities of the procedure are illustrated on the
basis of the use of pixellised sources, where the phase-locked sub-Poissonian
lasers or the degenerate optical parametric oscillator generating above
threshold are chosen as the pixels. The theory of the pixellised source of the
spatio-temporal squeezed light is elaborated as a part of this investigation.Comment: 11 pages, 5 figures, RevTeX4. Submitted to Phys. Rev.
Entanglement conditions for two-mode states: Applications
We examine the implications of several recently derived conditions [Hillery
and Zubairy, Phys. Rev. Lett. 96, 050503 (2006)] for determining when a
two-mode state is entangled. We first find examples of non-Gaussian states that
satisfy these conditions. We then apply the entanglement conditions to the
study of several linear devices, the beam splitter, the parametric amplifier,
and the linear phase-insensitive amplifier. For the first two, we find
conditions on the input states that guarantee that the output states are
entangled. For the linear amplifier, we determine in the limit of high and no
gain, when an entangled input leads to an entangled output. Finally, we show
how application of two two-mode entanglement conditions to a three-mode state
can serve as a test of genuine three-mode entanglement.Comment: 7 pages, no figures, replaced with published versio
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