20,212 research outputs found
Linking Ultracold Polar Molecules
We predict that pairs of polar molecules can be weakly bound together in an
ultracold environment, provided that a dc electric field is present. The field
that links the molecules together also strongly influences the basic properties
of the resulting dimer, such as its binding energy and predissociation
lifetime. Because of their long-range character these dimers will be useful in
disentangling cold collision dynamics of polar molecules. As an example, we
estimate the microwave photoassociation yield for OH-OH cold collisions.Comment: 4 pages 2 figure
Interference fringes with maximal contrast at finite coherence time
Interference fringes can result from the measurement of four-time fourth-order correlation functions of a wave field. These fringes have a statistical origin and, as a consequence, they show the greatest contrast when the coherence time of the field is finite. A simple acoustic experiment is presented in which these fringes are observed, and it is demonstrated that the contrast is maximal for partial coherence. Random telegraph phase noise is used to vary the field coherence in order to highlight the problem of interpreting this interference; for this noise, the Gaussian moment theorem may not be invoked to reduce the description of the interference to one in terms of first-order interference.M.W. Hamilto
Metamaterials for light rays: ray optics without wave-optical analog in the ray-optics limit
Volumes of sub-wavelength electromagnetic elements can act like homogeneous
materials: metamaterials. In analogy, sheets of optical elements such as prisms
can act ray-optically like homogeneous sheet materials. In this sense, such
sheets can be considered to be metamaterials for light rays (METATOYs).
METATOYs realize new and unusual transformations of the directions of
transmitted light rays. We study here, in the ray-optics and scalar-wave
limits, the wave-optical analog of such transformations, and we show that such
an analog does not always exist. Perhaps, this is the reason why many of the
ray-optical possibilities offered by METATOYs have never before been
considered.Comment: 10 pages, 3 figures, references update
Experimental verification of minima in excited long-range Rydberg states of Rb_2
Recent theoretical studies with alkali atoms A excited to high
Rydberg states predicted the existence of ultra long-range molecular bound
states. Such excited dimers have large electric dipole moments which, in
combination with their long radiative lifetimes, make them excellent candidates
for manipulation in applications. This letter reports on experimental
investigations of the self-broadening of Rb principal series lines, which
revealed multiple satellites in the line wings. The positions of the satellites
agree quantitatively with theoretically-predicted minima in the excited
long-range Rydberg states of Rb.Comment: 3 figures, 5 pages in two-column forma
Hard to recall but easy to judge: retrieval strategies in social information processing
The present research distinguishes two different retrieval modes: exhaustive and heuristic retrieval. Whereas exhaustive retrieval is elemental and retrieves specific memory traces, the output of heuristic retrieval is a memory composite. Different memory tasks depend upon these two retrieval modes in various degrees. Using a part-list cueing paradigm, we found a dissociation: providing part-list cues hindered the retrieval of the non-cued behaviors in free recall but boosted frequency estimates. In a second study, using a collaborative recall paradigm, each of three participants recalled one of the previously presented behaviors in turn. We hypothesized that behaviors recalled by other participants would become hyper-accessible, inhibiting the retrieval of non-recalled behaviors but boosting the corresponding frequency estimates relative to non-collaborative recall conditions. The results supported the hypotheses. The parallelism of the results of the two studies suggests that retrieval interference or inhibition is a crucial feature of social memory.info:eu-repo/semantics/acceptedVersio
Enhancing the comparability between part-list cueing and collaborative recall
The effects of part-list cueing and of collaborative recall in memory performance have
been recently addressed as parallel phenomena. Notably they both impair recall (and
boost frequency estimates) and they have been explained by the same underlying
mechanisms. However the comparability between the two paradigms is hindered by a
number of procedural differences. The main contribution of this paper is the
introduction of a new paradigm that makes standard part-list cueing and collaborative
recall more comparable. In our study we compared free recall and frequency estimates
of participants in a non-cueing condition with the same performance in a standard partlist cueing condition and in a condition in which part-list cues were gradually presented
during recall (as it occurs in collaborative recall). Results indicate that the effects of
part-list cueing continued to be reliable in both cueing conditions. Namely, recall was
impaired and frequency estimates were boosted relatively to a non-cueing condition.
The results obtained with this new method that enhances the direct comparability of the
two paradigms, provides further evidence for the parallel between the two effects.info:eu-repo/semantics/acceptedVersio
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Environmental monitoring and surveillance on the Oak Ridge Reservation: 1995 data
Environmental monitoring and surveillance are conducted on the Oak Ridge Reservation and its environs throughout the year. Environmental monitoring ensures that (1) the reservation is a safe place to work, (2) activities on the reservation do not adversely affect the neighboring communities, and (3) compliance is made with federal and state regulations. This document is a compilation of the monitoring and surveillance data for calendar year 1995. It is a tool for analysts in the fields of environmental monitoring and environmental restoration. The summary information found in the annual site environmental report was drawn from the contents of this document
Quaternion Analysis for Generalized Electromagnetic Fields of Dyons in Isotropic Medium
Quaternion analysis of time dependent Maxwell's equations in presence of
electric and magnetic charges has been developed and the solutions for the
classical problem of moving charges (electric and magnetic) are obtained in
unique, simple and consistent manner
On the spectra of the quantized action-variables of the compactified Ruijsenaars-Schneider system
A simple derivation of the spectra of the action-variables of the quantized
compactified Ruijsenaars-Schneider system is presented. The spectra are
obtained by combining Kahler quantization with the identification of the
classical action-variables as a standard toric moment map on the complex
projective space. The result is consistent with the Schrodinger quantization of
the system worked out previously by van Diejen and Vinet.Comment: Based on talk at the workshop CQIS-2011 (Protvino, Russia, January
2011), 12 page
Compression and diffusion: a joint approach to detect complexity
The adoption of the Kolmogorov-Sinai (KS) entropy is becoming a popular
research tool among physicists, especially when applied to a dynamical system
fitting the conditions of validity of the Pesin theorem. The study of time
series that are a manifestation of system dynamics whose rules are either
unknown or too complex for a mathematical treatment, is still a challenge since
the KS entropy is not computable, in general, in that case. Here we present a
plan of action based on the joint action of two procedures, both related to the
KS entropy, but compatible with computer implementation through fast and
efficient programs. The former procedure, called Compression Algorithm
Sensitive To Regularity (CASToRe), establishes the amount of order by the
numerical evaluation of algorithmic compressibility. The latter, called Complex
Analysis of Sequences via Scaling AND Randomness Assessment (CASSANDRA),
establishes the complexity degree through the numerical evaluation of the
strength of an anomalous effect. This is the departure, of the diffusion
process generated by the observed fluctuations, from ordinary Brownian motion.
The CASSANDRA algorithm shares with CASToRe a connection with the Kolmogorov
complexity. This makes both algorithms especially suitable to study the
transition from dynamics to thermodynamics, and the case of non-stationary time
series as well. The benefit of the joint action of these two methods is proven
by the analysis of artificial sequences with the same main properties as the
real time series to which the joint use of these two methods will be applied in
future research work.Comment: 27 pages, 9 figure
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