4,037 research outputs found
Life prediction of materials exposed to monotonic and cyclic loading: A technology survey and bibliography
Announced survey directs attention toward low cycle fatigue and thermal fatigue experienced at elevated temperatures equivalent to those found in hot end of gas turbine engine. Majority of bibliographic references are on life prediction for materials exposed to monotonic and cyclic loading in high temperature environments
Bloch oscillations of Path-Entangled Photons
We show that when photons in N-particle path entangled |N,0> + |0,N> state
undergo Bloch oscillations, they exhibit a periodic transition between
spatially bunched and antibunched states. The transition occurs even when the
photons are well separated in space. We study the scaling of the
bunching-antibunching period, and show it is proportional to 1/N.Comment: An error in figure 1b of the original manuscript was corrected, and
the period was redefine
Fracture toughness testing data: A technology survey and bibliography
Announced survey includes reports covering fracture toughness testing for various structural materials including information on plane strain and developing areas of mixed mode and plane strain test conditions. Bibliography references cite work and conclusions in fracture toughness testing and application of fracture toughness test data, and in fracture mechanics analysis
Cavity quantum electro-optics. II. Input-output relations between traveling optical and microwave fields
In the previous paper [M. Tsang, Phys. Rev. A 81, 063837 (2010), e-print
arXiv:1003.0116], I proposed a quantum model of a cavity electro-optic
modulator, which can coherently couple an optical cavity mode to a microwave
resonator mode and enable novel quantum operations on the two modes, including
laser cooling of the microwave mode, electro-optic entanglement, and
backaction-evading optical measurement of a microwave quadrature. In this
sequel, I focus on the quantum input-output relations between traveling optical
and microwave fields coupled to a cavity electro-optic modulator. With
red-sideband optical pumping, the relations are shown to resemble those of a
beam splitter for the traveling fields, so that in the ideal case of zero
parasitic loss and critical coupling, microwave photons can be coherently
up-converted to "flying" optical photons with unit efficiency, and vice versa.
With blue-sideband pumping, the modulator acts as a nondegenerate parametric
amplifier, which can generate two-mode squeezing and hybrid entangled photon
pairs at optical and microwave frequencies. These fundamental operations
provide a potential bridge between circuit quantum electrodynamics and quantum
optics.Comment: 12 pages, 10 figures, v2: updated and submitte
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
Decoherence-free preparation of Dicke states of trapped ions by collective stimulated Raman adiabatic passage
We propose a simple technique for the generation of arbitrary-sized Dicke
states in a chain of trapped ions. The method uses global addressing of the
entire chain by two pairs of delayed but partially overlapping laser pulses to
engineer a collective adiabatic passage along a multi-ion dark state. Our
technique, which is a many-particle generalization of stimulated Raman
adiabatic passage (STIRAP), is decoherence-free with respect to spontaneous
emission and robust against moderate fluctuations in the experimental
parameters. Furthermore, because the process is very rapid, the effects of
heating are almost negligible under realistic experimental conditions. We
predict that the overall fidelity of synthesis of a Dicke state involving ten
ions sharing two excitations should approach 98% with currently achievable
experimental parameters.Comment: 14 pages, 8 figure
Conditional preparation of states containing a definite number of photons
A technique for conditionally creating single- or multimode photon-number
states is analyzed using Bayesian theory. We consider the heralded N-photon
states created from the photons produced by an unseeded optical parametric
amplifier when the heralding detector is the time-multiplexed
photon-number-resolving detector recently demonstrated by Fitch, et al. [Phys.
Rev. A 68, 043814 (2003).] and simultaneously by Achilles, et al. [Opt. Lett.
28, 2387 (2003).]. We find that even with significant loss in the heralding
detector, fields with sub-Poissonian photon-number distributions can be
created. We also show that heralded multimode fields created using this
technique are more robust against detector loss than are single-mode fields.Comment: 6 pages, 6 figures, reference added, typos corrected, content update
Passive decoy state quantum key distribution: Closing the gap to perfect sources
We propose a quantum key distribution scheme which closely matches the
performance of a perfect single photon source. It nearly attains the physical
upper bound in terms of key generation rate and maximally achievable distance.
Our scheme relies on a practical setup based on a parametric downconversion
source and present-day, non-ideal photon-number detection. Arbitrary
experimental imperfections which lead to bit errors are included. We select
decoy states by classical post-processing. This allows to improve the effective
signal statistics and achievable distance.Comment: 4 pages, 3 figures. State preparation correcte
Invariant information and complementarity in high-dimensional states
Using a generalization of the invariant information introduced by Brukner and
Zeilinger [Phys. Rev. Lett. \textbf{83}, 3354 (1999)] to high-dimensional
systems, we introduce a complementarity relation between the local and nonlocal
information for systems under the isolated environment, where
is prime or the power of prime. We also analyze the dynamics of the local
information in the decoherence process.Comment: 4 pages, 2 figure
Truncated states obtained by iteration
Quantum states of the electromagnetic field are of considerable importance,
finding potential application in various areas of physics, as diverse as solid
state physics, quantum communication and cosmology. In this paper we introduce
the concept of truncated states obtained via iterative processes (TSI) and
study its statistical features, making an analogy with dynamical systems theory
(DST). As a specific example, we have studied TSI for the doubling and the
logistic functions, which are standard functions in studying chaos. TSI for
both the doubling and logistic functions exhibit certain similar patterns when
their statistical features are compared from the point of view of DST. A
general method to engineer TSI in the running-wave domain is employed, which
includes the errors due to the nonidealities of detectors and photocounts.Comment: 10 pages, 22 figure
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