122,492 research outputs found
Cavity QED determination of atomic number statistics in optical lattices
We study the reflection of two counter-propagating modes of the light field
in a ring resonator by ultracold atoms either in the Mott insulator state or in
the superfluid state of an optical lattice. We obtain exact numerical results
for a simple two-well model and carry out statistical calculations appropriate
for the full lattice case. We find that the dynamics of the reflected light
strongly depends on both the lattice spacing and the state of the matter-wave
field. Depending on the lattice spacing, the light field is sensitive to
various density-density correlation functions of the atoms. The light field and
the atoms become strongly entangled if the latter are in a superfluid state, in
which case the photon statistics typically exhibit complicated multimodal
structures.Comment: 10 pages revtex, 13 figure
On the parameters of the Kerr-NUT-(anti-)de Sitter space-time
Different forms of the metric for the Kerr-NUT-(anti-)de Sitter space-time
are being widely used in its extension to higher dimensions. The purpose of
this note is to relate the parameters that are being used to the physical
parameters (mass, rotation, NUT and cosmological constant) in the basic four
dimensional situation.Comment: 4 pages. To appear as a Note in Classical and Quantum Gravit
Landscape phage, phage display, stripped phage, biosensors, detection, affinity reagent, nanotechnology, Salmonella typhimurium, Bacillus anthracis
Filamentous phage, such as fd used in this study, are thread-shaped bacterial
viruses. Their outer coat is a tube formed by thousands equal copies of the
major coat protein pVIII. We constructed libraries of random peptides fused to
all pVIII domains and selected phages that act as probes specific for a panel
of test antigens and biological threat agents. Because the viral carrier is
infective, phage borne bio-selective probes can be cloned individually and
propagated indefinitely without needs of their chemical synthesis or
reconstructing. We demonstrated the feasibility of using landscape phages and
their stripped fusion proteins as new bioselective materials that combine
unique characteristics of affinity reagents and self assembling membrane
proteins. Biorecognition layers fabricated from phage-derived probes bind
biological agents and generate detectable signals. The performance of
phage-derived materials as biorecognition films was illustrated by detection of
streptavidin-coated beads, Bacillus anthracis spores and Salmonella typhimurium
cells. With further refinement, the phage-derived analytical platforms for
detecting and monitoring of numerous threat agents may be developed, since the
biodetector films may be obtained from landscape phages selected against any
bacteria, virus or toxin. As elements of field-use detectors, they are superior
to antibodies, since they are inexpensive, highly specific and strong binders,
resistant to high temperatures and environmental stresses.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Entanglement of macroscopic test masses and the Standard Quantum Limit in laser interferometry
We show that the generation of entanglement of two heavily macroscopic
mirrors with masses of up to several kilograms are feasible with state of the
art techniques of high-precision laser interferometry. The basis of such a
demonstration would be a Michelson interferometer with suspended mirrors and
simultaneous homodyne detections at both interferometer output ports. We
present the connection between the generation of entanglement and the Standard
Quantum Limit (SQL) for a free mass. The SQL is a well-known reference limit in
operating interferometers for gravitational-wave detection and provides a
measure of when macroscopic entanglement can be observed in the presence of
realistic decoherence processes
Negative optical inertia for enhancing the sensitivity of future gravitational-wave detectors
We consider enhancing the sensitivity of future gravitational-wave detectors
by using double optical spring. When the power, detuning and bandwidth of the
two carriers are chosen appropriately, the effect of the double optical spring
can be described as a "negative inertia", which cancels the positive inertia of
the test masses and thus increases their response to gravitational waves. This
allows us to surpass the free-mass Standard Quantum Limit (SQL) over a broad
frequency band, through signal amplification, rather than noise cancelation,
which has been the case for all broadband SQL-beating schemes so far considered
for gravitational-wave detectors. The merit of such signal amplification
schemes lies in the fact that they are less susceptible to optical losses than
noise cancelation schemes. We show that it is feasible to demonstrate such an
effect with the {\it Gingin High Optical Power Test Facility}, and it can
eventually be implemented in future advanced GW detectors.Comment: 7 pages, 3 figure
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