4030
1994
eng
postprint
0
2010-04-29
--
--
A modulated mirror for atomic interferometry
A novel atomic beam splitter, using reflection of atoms off an evanescent light wave, is investigated theoretically. The intensity or frequency of the light is modulated in order to create sidebands on the reflected de Broglie wave. The weights and phases of the various sidevands are calculated using three different approaches: the Born approximation, a semiclassical path integral approach, and a numerical solution of the time-dependent Schrdinger equation. We show how this modulated mirror could be used to build practical atomic interferometers.
urn:nbn:de:kobv:517-opus-42279
4227
Journal de Physique 4 (1994) 11, S. 1877-1896
<hr>The preprint is available at ArXiv.org:
<br>
<a href="http://de.arxiv.org/abs/quant-ph/0408156">Atomic diffraction by a thin phase grating</a>; In: Journal de Physique. - 4 (1994) 11, S. 1877-1896<br>
egger@...
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Carsten Henkel
Andrew M. Steane
Robin Kaiser
Jean Dalibard
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
paper 102
Physik
open_access
Institut für Physik und Astronomie
Universität Potsdam
https://publishup.uni-potsdam.de/files/4030/modulated.pdf
1831
2006
eng
postprint
0
2008-09-10
--
--
About the derivation of the SCA algorithm
In Allefeld & Kurths [2004], we introduced an approach to multivariate phase synchronization analysis in the form of a Synchronization Cluster Analysis (SCA). A statistical model of a synchronization cluster was described, and an abbreviated instruction on how to apply this model to empirical data was given, while an implementation of the corresponding algorithm was (and is) available from the authors. In this letter, the complete details on how the data analysis algorithm is to be derived from the model are filled in.
urn:nbn:de:kobv:517-opus-20137
2013
International Journal of Bifurcation and Chaos. - 16 (2006), 12, pp. 3705–3706. ISSN (print) 0218-1274, ISSN (online)
<hr>
Electronic version of an article published as<br><a href="http://www.worldscinet.com/ijbc/ijbc.shtml
">
International Journal of Bifurcation and Chaos. </a> - 16 (2006), 12, pp. 3705–3706
<br>
ISSN (print) 0218-1274<br>
ISSN (online) 1793-6551 <br>DOI <a href="http://dx.doi.org/10.1142/S0218127406017099">10.1142/S0218127406017099
</a><br>
© World Scientific Publishing Company
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Carsten Allefeld
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
paper 075
Physik
open_access
Institut für Physik und Astronomie
Universität Potsdam
https://publishup.uni-potsdam.de/files/1831/allefeld_2006.pdf
1828
2004
eng
postprint
0
2008-09-10
--
--
An approach to multivariate phase synchronization analysis and its application to event-related potentials
A method for the multivariate analysis of statistical phase synchronization phenomena in empirical data is presented. A first statistical approach is complemented by a stochastic dynamic model, to result in a data analysis algorithm which can in a specific sense be shown to be a generic multivariate statistical phase synchronization analysis. The method is applied to EEG data from a psychological experiment, obtaining results which indicate the relevance of this method in the context of cognitive science as well as in other fields.
urn:nbn:de:kobv:517-opus-20106
2010
International Journal of Bifurcation and Chaos. - 14 (2004), 2, pp. 417 - 426. ISSN (print) 0218-1274, ISSN (online)
<hr>
Electronic version of an article published as<br><a href="http://www.worldscinet.com/ijbc/ijbc.shtml
">
International Journal of Bifurcation and Chaos. </a> - 14 (2004), 2, pp. 417 - 426
<br>
ISSN (print) 0218-1274<br>
ISSN (online) 1793-6551 <br>DOI <a href="http://dx.doi.org/10.1142/S0218127404009521">10.1142/S0218127404009521
</a><br>
© World Scientific Publishing Company
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Carsten Allefeld
Jürgen Kurths
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
paper 069
Physik
open_access
Institut für Physik und Astronomie
Universität Potsdam
https://publishup.uni-potsdam.de/files/1828/allefeld_kurths_2004.pdf
4029
1994
eng
postprint
0
2010-04-29
--
--
Atomic diffraction by a thin phase grating
We present a semiclassical perturbation method for the description of atomic diffraction by a weakly modulated potential. It proceeds in a way similar to the treatment of light diffraction by a thin phase grating, and consists in calculating the atomic wavefunction by means of action integrals along the classical trajectories of the atoms in the absence of the modulated part of the potential. The capabilities and the validity condition of the method are illustrated on the well-known case of atomic diffraction by a Gaussian standing wave. We prove that in this situation the perturbation method is equivalent to the Raman-Nath approximation, and we point out that the usually-considered Raman-Nath validity condition can lead to inaccuracies in the evaluation of the phases of the diffraction amplitudes. The method is also applied to the case of an evanescent wave reflection grating, and an analytical expression for the diffraction pattern at any incidence angle is obtained for the first time. Finally, the application of the method to other situations is briefly discussed.
urn:nbn:de:kobv:517-opus-42269
4226
Journal de Physique 4 (1994) 11, S. 1955-1974
<hr>The preprint is available at ArXiv.org:
<br>
<a href="http://arxiv.org/abs/quant-ph/0408154v1">Atomic diffraction by a thin phase grating</a>; In: Journal de Physique. - 4 (1994) 11, S. 1955-1974<br>
egger@...
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Carsten Henkel
Jean-Yves Courtois
Alain Aspect
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
paper 101
Physik
open_access
Institut für Physik und Astronomie
Universität Potsdam
https://publishup.uni-potsdam.de/files/4029/diffraction.pdf
1830
2005
eng
postprint
0
2008-09-10
--
--
Detection of early cognitive processing by event-related phase synchronization analysis
In order to investigate the temporal characteristics of cognitive processing, we apply multivariate phase synchronization analysis to event-related potentials. The experimental design combines a semantic incongruity in a sentence context with a physical mismatch (color change). In the ERP average, these result in an N400 component and a P300-like positivity, respectively. The synchronization analysis shows an effect of global desynchronization in the theta band around 288ms after stimulus presentation for the semantic incongruity, while the physical mismatch elicits an increase of global synchronization in the alpha band around 204ms. Both of these effects clearly precede those in the ERP average. Moreover, the delay between synchronization effect and ERP component correlates with the complexity of the cognitive processes.
urn:nbn:de:kobv:517-opus-20126
2012
Neuroreport. - 16 (2005), 1, pp. 13 - 16. ISSN (print) 0959-4965, ISSN (online) 1473-558X
<hr>This is a preprint of the article first published in:<br>
<a href="http://www.neuroreport.com/pt/re/neuroreport/toc.00001756-200501190-00000.htm;jsessionid=LHpTXw3g1XhGMFVw7Ts1QnwGNhG0FFc4TGSzZMmnjqn7yMTKsBlr!609209752!181195628!8091!-1
">
Neuroreport. </a> - 16 (2005), 1, pp. 13 - 16<br>
ISSN (print) 0959-4965<br>
ISSN (online) 1473-558X
</a><br>
It is not the final version published by <br><a href="http://www.lww.com/index.html">Lippincott, Williams & Wilkins</a>.
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Carsten Allefeld
Stefan Frisch
Matthias Schlesewsky
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
paper 074
eng
uncontrolled
phase synchronization
eng
uncontrolled
coherence
eng
uncontrolled
semantic incongruity
eng
uncontrolled
color change
eng
uncontrolled
N400
eng
uncontrolled
P300
eng
uncontrolled
theta
eng
uncontrolled
alpha
Physik
open_access
Institut für Physik und Astronomie
Extern
Universität Potsdam
https://publishup.uni-potsdam.de/files/1830/allefeld_etal_2005.pdf
5489
2006
eng
postprint
0
2011-12-07
--
--
Generating Surrogates from Recurrences
In this paper we present an approach to recover the dynamics from recurrences of a system and then generate (multivariate) twin surrogate (TS) trajectories. In contrast to other approaches, such as the linear-like surrogates, this technique produces surrogates which correspond to an independent copy of the underlying system, i. e. they induce a trajectory of the underlying system visiting the attractor in a different way. We show that these surrogates are well suited to test for complex synchronization, which makes it possible to systematically assess the reliability of synchronization analyses. We then apply the TS to study binocular fixational movements and find strong indications that the fixational movements of the left and right eye are phase synchronized. This result indicates that there might be one centre only in the brain that produces the fixational movements in both eyes or a close link between two centres.
urn:nbn:de:kobv:517-opus-56906
5690
Philosophical Transactions of the Royal Society - Series A. - ISSN 1471-2962. - 366 (2008), S. 545-557
first published in: <br/>
<a href="http://rsta.royalsocietypublishing.org/">Philosophical Transactions of the Royal Society - Series A</a> (2008), 366 : S. 545-557 <br/>
<a href="http://dx.doi.org/10.1098/rsta.2007.2109">DOI:10.1098/rsta.2007.2109</a> <br/>
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Marco Thiel
Maria Carmen Romano
Jürgen Kurths
Martin Rolfs
Reinhold Kliegl
Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe
paper 238
eng
uncontrolled
Æ Recurrence Plots
eng
uncontrolled
Surrogate Data
eng
uncontrolled
Hypothesis Test
eng
uncontrolled
Phase Synchronization
Sprache
open_access
Institut für Physik und Astronomie
Department Psychologie
Institut für Psychologie
Universität Potsdam
https://publishup.uni-potsdam.de/files/5489/phr_238_2011_12_07.pdf
47486
2015
2020
eng
30134
30147
16
980
postprint
0
2020-08-27
2020-08-27
--
Geometry controlled anomalous diffusion in random fractal geometries
We investigate the ergodic properties of a random walker performing (anomalous) diffusion on a random fractal geometry. Extensive Monte Carlo simulations of the motion of tracer particles on an ensemble of realisations of percolation clusters are performed for a wide range of percolation densities. Single trajectories of the tracer motion are analysed to quantify the time averaged mean squared displacement (MSD) and to compare this with the ensemble averaged MSD of the particle motion. Other complementary physical observables associated with ergodicity are studied, as well. It turns out that the time averaged MSD of individual realisations exhibits non-vanishing fluctuations even in the limit of very long observation times as the percolation density approaches the critical value. This apparent non-ergodic behaviour concurs with the ergodic behaviour on the ensemble averaged level. We demonstrate how the non-vanishing fluctuations in single particle trajectories are analytically expressed in terms of the fractal dimension and the cluster size distribution of the random geometry, thus being of purely geometrical origin. Moreover, we reveal that the convergence scaling law to ergodicity, which is known to be inversely proportional to the observation time T for ergodic diffusion processes, follows a power-law ∼T−h with h < 1 due to the fractal structure of the accessible space. These results provide useful measures for differentiating the subdiffusion on random fractals from an otherwise closely related process, namely, fractional Brownian motion. Implications of our results on the analysis of single particle tracking experiments are provided.
Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
looking beyond the infinite cluster
10.25932/publishup-47486
urn:nbn:de:kobv:517-opus4-474864
1866-8372
Physical Chemistry Chemical Physics 17 (2015) 44, 30134-30147 DOI:10.1039/C5CP03548A
30134
<a href="http://publishup.uni-potsdam.de/39283">Bibliographieeintrag der Originalveröffentlichung/Quelle</a>
<a href="http://publishup.uni-potsdam.de/47276">This article is a part of this cumulative dissertation</a>
true
true
Yousof Mardoukhi
Jae-Hyung Jeon
Ralf Metzler
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
980
eng
uncontrolled
plasma-membrane
eng
uncontrolled
mechanisms
eng
uncontrolled
motion
eng
uncontrolled
nonergodicity
eng
uncontrolled
models
Chemie und zugeordnete Wissenschaften
open_access
Institut für Physik und Astronomie
Referiert
Green Open-Access
Universität Potsdam
https://publishup.uni-potsdam.de/files/47486/pmnr980.pdf
4031
1994
eng
postprint
0
2010-04-29
--
--
Phase shifts of atomic de Broglie waves at an evanescent wave mirror
A detailed theoretical investigation of the reflection of an atomic de Broglie wave at an evanescent wave mirror is presented. The classical and the semiclassical descriptions of the reflection process are reviewed, and a full wave-mechanical approach based on the analytical soution of the corresponding Schrödinger equation is presented. The phase shift at reflection is calculated exactly and interpreted in terms of instantaneous reflection of the atom at an effective mirror. Besides the semiclassical regime of reflection describable by the WKB method, a pure quantum regime of reflection is identified in the limit where the incident de Broglie wavelength is large compared to the evanescent wave decay length.
urn:nbn:de:kobv:517-opus-42289
4228
Laser Physics 4 (1994), S. 1042-1049, ISSN 1054-660X
egger@...
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Carsten Henkel
Jean-Yves Courtois
Robin Kaiser
C. Westbrook
Alain Aspect
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
paper 103
Physik
open_access
Institut für Physik und Astronomie
Universität Potsdam
https://publishup.uni-potsdam.de/files/4031/phase_shift.pdf
1829
2004
eng
postprint
0
2008-09-10
--
--
Phase synchronization analysis of event-related potentials in language processing
Phase synchronization analysis, including our recently introduced multivariate approach, is applied to event-related EEG data from an experiment on language processing, following a classic psycholinguistic paradigm. For the two types of experimental manipulation distinct effects in overall synchronization are found; for one of them they can also be localized. The synchronization effects occur earlier than those found by the conventional analysis method, indicating that the new approach provides additional information on the underlying neuronal process.
urn:nbn:de:kobv:517-opus-20113
2011
Experimental Chaos: 8th Experimental Chaos Conference. AIP Conference Proceedings. - 742 (2004), pp. 106 - 111. ISSN (print) 0094-243X, ISSN (online) 0094-243X
<hr>
first published in:<br><a href="http://scitation.aip.org/proceedings/
">
Experimental Chaos: 8th Experimental Chaos Conference. AIP Conference Proceedings. </a> -742 (2004), pp. 106 - 111<br>
ISSN (print) 0094-243X<br>
ISSN (online) 0094-243X<br>DOI <a href="http://dx.doi.org/10.1063/1.1846466">10.1063/1.1846466
</a><br>
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Carsten Allefeld
Stefan Frisch
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
paper 073
Physik
open_access
Institut für Physik und Astronomie
Department Linguistik
Institut für Linguistik / Allgemeine Sprachwissenschaft
Universität Potsdam
https://publishup.uni-potsdam.de/files/1829/allefeld_frisch_2004.pdf
1827
2004
eng
postprint
0
2008-09-10
--
--
Testing for phase synchronization
We present different tests for phase synchronization which improve the procedures currently used in the literature. This is accomplished by using a two-samples test setup and by utilizing insights and methods from directional statistics and bootstrap theory. The tests differ in the generality of the situation in which they can be applied as well as in their complexity, including computational cost. A modification of the resampling technique of the bootstrap is introduced, making it possible to fully utilize data from time series.
urn:nbn:de:kobv:517-opus-20091
2009
International Journal of Bifurcation and Chaos. - 14 (2004), 2, pp. 405–416. ISSN (print) 0218-1274, ISSN (online)
<hr>
Electronic version of an article published as<br><a href="http://www.worldscinet.com/ijbc/ijbc.shtml
">
International Journal of Bifurcation and Chaos. </a> - 14 (2004), 2, pp. 405–416
<br>
ISSN (print) 0218-1274<br>
ISSN (online) 1793-6551 <br>DOI <a href="http://dx.doi.org/10.1142/S021812740400951X">10.1142/S021812740400951X
</a><br>
© World Scientific Publishing Company
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Carsten Allefeld
Jürgen Kurths
Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
paper 071
Physik
open_access
Institut für Physik und Astronomie
Universität Potsdam
https://publishup.uni-potsdam.de/files/1827/allefeld_kurths_2004.pdf
5522
2006
eng
postprint
0
2011-12-13
--
--
Twin Surrogates to Test for Complex Synchronisation
We present an approach to generate (multivariate) twin surrogates (TS) based on recurrence properties. This technique generates surrogates which correspond to an independent copy of the underlying system, i. e. they induce a trajectory of the underlying system starting at different initial conditions. We show that these surrogates are well suited to test for complex synchronisation and exemplify this for the paradigmatic system of R¨ossler oscillators. The proposed test enables to assess the statistical relevance of a synchronisation analysis from passive experiments which are typical in natural systems.
urn:nbn:de:kobv:517-opus-57231
5723
Europhysics Letters: a letters journal exploring the frontiers of physics. - ISSN 0295-5075. - 75 (2006), 4, S. 535 - 541
first published in:<br/>
<a href="https://www.epletters.net/4DCGI/_general&presentation/-1/0/0/0/0/0/404054498">Europhysics Letters: a letters journal exploring the frontiers of physics</a><br/>
<a href="http://dx.doi.org/10.1209/epl/i2006-10147-0"<DOI: 10.1209/epl/i2006-10147-0</a><br/>
EDP Sciences
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Marco Thiel
Maria Carmen Romano
Jürgen Kurths
Martin Rolfs
Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe
paper 264
Sprache
open_access
Institut für Physik und Astronomie
Department Psychologie
Institut für Psychologie
Universität Potsdam
https://publishup.uni-potsdam.de/files/5522/phr_264_2011_12_13.pdf