1,182 research outputs found
Collective Feshbach scattering of a superfluid droplet from a mesoscopic two-component Bose-Einstein condensate
We examine the collective scattering of a superfluid droplet impinging on a
mesoscopic Bose-Einstein condensate (BEC) as a target. The BEC consists of an
atomic gas with two internal electronic states, each of which is trapped by a
finite-depth external potential. An off-resonant optical laser field provides a
localized coupling between the BEC components in the trapping region. This
mesoscopic scenario matches the microscopic setup for Feshbach scattering of
two particles, when a bound state of one sub-manifold is embedded in the
scattering continuum of the other sub-manifold. Within the mean-field picture,
we obtain resonant scattering phase shifts from a linear response theory in
agreement with an exact numerical solution of the real time scattering process
and simple analytical approximations thereof. We find an energy-dependent
transmission coefficient that is controllable via the optical field between 0
and 100%.Comment: 4 Latex pages, including 4 figure
The central consciousness technique; a study of three works by Henry James
This paper will consider the development of the central consciousness technique in three of Henry James\u27 works; Madame de Mauves, The Portrait of a Lady, and The Beast in the Jungle
Formation of Pairing Fields in Resonantly Coupled Atomic and Molecular Bose-Einstein Condensates
In this paper, we show that pair-correlations may play an important role in
the quantum statistical properties of a Bose-Einstein condensed gas composed of
an atomic field resonantly coupled with a corresponding field of molecular
dimers. Specifically, pair-correlations in this system can dramatically modify
the coherent and incoherent transfer between the atomic and molecular fields.Comment: 4 pages, 4 figure
Equivalence of Kinetic Theories of Bose-Einstein Condensation
We discuss the equivalence of two non-equilibrium kinetic theories that
describe the evolution of a dilute, Bose-Einstein condensed atomic gas in a
harmonic trap. The second-order kinetic equations of Walser et al. [PRA 63,
013607 (2001)] reduce to the Gross-Pitaevskii equation and the quantum
Boltzmann equation in the low and high temperature limits, respectively. These
kinetic equations can thus describe the system in equilibrium (finite
temperature) as well as in non-equilibrium (real time). We have found this
theory to be equivalent to the non-equilibrium Green's function approach
originally proposed by Kadanoff and Baym and more recently applied to
inhomogeneous trapped systems by M. Imamovi\'c-Tomasovi\'c and A. Griffin
[arXiv:cond-mat/9911402].Comment: REVTeX3, 6 pages, 2 eps figures, published version, minor change
Laser-noise-induced correlations and anti-correlations in Electromagnetically Induced Transparency
High degrees of intensity correlation between two independent lasers were
observed after propagation through a rubidium vapor cell in which they generate
Electromagnetically Induced Transparency (EIT). As the optical field
intensities are increased, the correlation changes sign (becoming
anti-correlation). The experiment was performed in a room temperature rubidium
cell, using two diode lasers tuned to the Rb line (nm). The cross-correlation spectral function for the pump and probe fields
is numerically obtained by modeling the temporal dynamics of both field phases
as diffusing processes. We explored the dependence of the atomic response on
the atom-field Rabi frequencies, optical detuning and Doppler width. The
results show that resonant phase-noise to amplitude-noise conversion is at the
origin of the observed signal and the change in sign for the correlation
coefficient can be explained as a consequence of the competition between EIT
and Raman resonance processes.Comment: Accepted for publication in EPJ
The Stanley Foundation Bipolar Network: Results of the naturalistic follow-up study after 2.5 years of follow-up in the German centres
The Stanley Foundation Bipolar Network (SFBN) is an international, multisite network investigating the characteristics and course of bipolar disorder. Methods (history, ratings and longitudinal follow-up) are standardized and equally applied in all 7 centres. This article describes demographics and illness characteristics of the first 152 German patients enrolled in them SFBN as well as the results of 2.5 years of follow-up. Patients in Germany were usually enrolled after hospitalisation. More than 72% of the study population suffered from bipolar I disorder and 25% from bipolar 11 disorder. The mean +/- SD age of the study participants was 42.08 +/- 13.5 years, and the mean SD age of onset 24.44 +/- 10.9 years. More than 40% of the sample reported a rapid-cycling course in history, and even more a cycle acceleration overtime. 37% attempted suicide at least once. 36% had an additional Axis I disorder, with alcohol abuse being the most common one, followed by anxiety disorders. During the follow-up period, only 27% remained stable, 56% had a recurrence, 12.8% perceived subsyndromal symptoms despite treatment and regular visits. 27% suffered from a rapid-cycling course during the follow-up period. Recurrences were significantly associated with bipolar I disorder, an additional comorbid Axis I disorder, rapid cycling in history, a higher number of mood stabilizers and the long-term use of typical antipsychotics. Rapid cycling during follow-up was only associated with a rapidcycling course in history, a higher number of mood stabilizers and at least one suicide attempt in history. Copyright (c) 2003 S. Karger AG, Basel
Dissociating sub-processes of aftereffects of completed intentions and costs to the ongoing task in prospective memory: A mouse-tracking approach
In the present study, we used mouse tracking to investigate two processes underlying prospective memory (PM) retrieval: First, we aimed to explore to what extent spontaneous retrieval of already completed PM intentions is supported by reflexive-associative and discrepancy-plus-search processes. Second, we aimed to disentangle whether costs to an ongoing task during the pursuit of a PM intention are associated with presumably resource-demanding monitoring processes or with a presumably resource-sparing strategic delay of ongoing-task responses. Our third aim was to explore the interaction of processes underlying costs to the ongoing task and processes of spontaneous retrieval. Our analyses replicated response-time patterns from previous studies indicating aftereffects of completed intentions and costs to ongoing-task performance, as well as increased aftereffects while pursuing a PM intention. Notably, based on our mouse-tracking analyses, we argue that aftereffects of completed intentions are best explained by a reflexive initiation of an already completed intention. If the completed intention is not performed in its entirety (i.e., no commission error), the reflexive initiation of the completed intention is followed by a subsequent movement correction that most likely represents a time-consuming response-verification process. Regarding performance costs in the ongoing task, our analyses suggest that actively pursuing a PM intention most likely leads to a strategic delay of ongoing activities. Lastly, we found that pursuing a novel PM task after intention completion exacerbated orienting responses to all deviant stimuli, exacerbated the readiness to initiate the completed intention reflexively, and substantially prolonged the response-verification process following this reflexive intention retrieval
Kinetic theory and dynamic structure factor of a condensate in the random phase approximation
We present the microscopic kinetic theory of a homogeneous dilute Bose
condensed gas in the generalized random phase approximation (GRPA), which
satisfies the following requirements: 1) the mass, momentum and energy
conservation laws; 2) the H-theorem; 3) the superfluidity property and 4) the
recovery of the Bogoliubov theory at zero temperature \cite{condenson}. In this
approach, the condensate influences the binary collisional process between the
two normal atoms, in the sense that their interaction force results from the
mediation of a Bogoliubov collective excitation traveling throughout the
condensate. Furthermore, as long as the Bose gas is stable, no collision
happens between condensed and normal atoms. In this paper, we show how the
kinetic theory in the GRPA allows to calculate the dynamic structure factor at
finite temperature and when the normal and superfluid are in a relative motion.
The obtained spectrum for this factor provides a prediction which, compared to
the experimental results, allows to validate the GRPA.
PACS numbers:03.75.Hh, 03.75.Kk, 05.30.-dComment: 6 pages, 1 figures, QFS2004 conferenc
Entwicklung eines generischen Gemeindereferenzprozess-modells in Anlehnung an das ARIS-Modell
Die durchgängige Einführung von E-Government geht im Gegensatz zum Thema E- Business in der Privatwirtschaft eher beschaulich voran. Dies hängt u.a. auch damit zusammen, dass an der Schnittstelle von Verwaltung und IT noch größerer Entwicklungsbedarf ersichtlich ist. Konzeptionell ist dazu noch einige Grundlagenarbeit zu leisten, bis hier mehr Konsistenz in eine Verwaltungseinheits-übergreifende Entwicklung entsteht, sodass sich Interoperabilität zu einem durchgängig umgesetzten Prinzip etabliert. Dieser Beitrag schildert ein integriertes Konzept aus Sicht von Gemeindeverwaltungen, das aber auf allen föderalen Ebenen umgesetzt werden kann. Das Konzept dient der Abbildung von Geschäftsprozessen und den damit verbundenen Aspekten wie Formulare, Informationen, Leistungen, Aufgaben-, Kompetenzund Veranwortungs-Zuordnungen sowie Organisationsund Governance-Aspekten. Als Grundlage dazu dient das für das vorliegende Vorhaben adaptierte ARIS-Modell. In einem iterativen Vorgehen ist das Modell mit Gemeindemitarbeitenden auf die Bedürfnisse einer Gemeinde angepasst worden. Die vorliegende Prozesslandkarte ist in die Bereiche Governance-, Führungs-, Kernund Unterstützungsaufgaben gegliedert. Differenziert werden die folgenden Sichten auf Prozessebene: Eigentliche Prozesssicht, Organisationssicht mit Aufgaben, Verantwortungen und Zuständigkeiten, Informationssicht mit Formularen, Dokumenten und relevanten Gesetzen, Sicht auf Kontrollflüsse, Gateways und Geschäftsregeln sowie die Sicht auf die vom Prozessablauf betroffenen IT-Systeme
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